Methods and systems for spillback control of in-line mixing of hydrocarbon liquids

ABSTRACT

Methods and systems of admixing hydrocarbon liquids from two or more sets of tanks into a single pipeline to provide in-line mixing thereof. In an embodiment of the in-line mixing system, hydrocarbon liquids stored in at least one tank of each of two or more sets of tanks positioned at a tank farm are blended into a blend flow pipe via in-line mixing and the blended mixture is pumped through a single pipeline. In one or more embodiments, the in-line mixing system employs a separate spillback or recirculation loop that is fluidly connected to each set of the two or more sets of tanks to control the flow of the hydrocarbon fluid/liquid from each set of tanks to the blend flow pipe. Associated methods of operating one or more embodiments of the system include regulation of spillback or recirculation loop flow rate and/or pressure to drive the actual blend ratio towards a desired blend ratio.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation-in-Part of U.S. applicationSer. No. 17/247,700, filed Dec. 21, 2020, titled “METHODS AND SYSTEMSFOR INLINE MIXING OF HYDROCARBON LIQUIDS BASED ON DENSITY OR GRAVITY”,which claims priority to and the benefit of U.S. Provisional ApplicationNo. 63/198,356, filed Oct. 13, 2020, titled “METHODS AND SYSTEMS FORINLINE MIXING OF PETROLEUM LIQUIDS,” U.S. Provisional Application No.62/705,538, filed Jul. 2, 2020, titled “METHODS AND SYSTEMS FOR INLINEMIXING OF PETROLEUM LIQUIDS”, and U.S. Provisional Application No.62/954,960, filed Dec. 30, 2019, titled “METHOD AND APPARATUS FOR INLINEMIXING OF HEAVY CRUDE”, and, the disclosures of which are incorporatedherein by reference in their entirety. The present application isfurther a Continuation-in-Part of U.S. application Ser. No. 17/247,704,filed Dec. 21, 2020, titled “METHODS AND SYSTEMS FOR INLINE MIXING OFHYDROCARBON LIQUIDS”, which claims priority to and the benefit of U.S.Provisional Application No. 63/198,356, filed Oct. 13, 2020, titled“METHODS AND SYSTEMS FOR INLINE MIXING OF PETROLEUM LIQUIDS,” U.S.Provisional Application No. 62/705,538, filed Jul. 2, 2020, titled“METHODS AND SYSTEMS FOR INLINE MIXING OF PETROLEUM LIQUIDS”, and U.S.Provisional Application No. 62/954,960, filed Dec. 30, 2019, titled“METHOD AND APPARATUS FOR INLINE MIXING OF HEAVY CRUDE”, the disclosuresof which are incorporated herein by reference in their entirety.

FIELD OF DISCLOSURE

The disclosure herein relates to systems and methods for providingin-line mixing of hydrocarbon liquids, and one or more embodiments ofsuch systems and methods may be suitable for providing multi-componentmixing of two or more hydrocarbon liquids.

BACKGROUND

Different types of hydrocarbon liquids, such as petroleum and renewableliquid products (e.g., such as crude oil), are often mixed upstream of arefinery to reduce the viscosity of heavy crude and maximize capacity,or to create a desired set of properties (TAN, sulfur, etc.). Given themultitude of crude types, the potential mixtures and component ratiosare numerous. In some situations, multiple different types ofhydrocarbon liquids, e.g., crude oil and renewable products, fromdifferent tanks may need to be mixed in a particular ratio. Further,there may also be a need to create a desired mixture on demand and shipthe mixture through a pipeline as one homogenous product. In suchexamples, the mixing of different types of hydrocarbon liquid, e.g.,crude and renewable liquid, may be performed at a pipeline originationstation. Often, the pipeline origination station may include a tank farm(e.g., having multiple tanks for storage and mixing of the crude oils)and extensive piping capable of transporting hydrocarbon liquids fromeach of the tanks to one or more mainline booster pumps, which raise thehydrocarbon liquids to high pressures for traveling on a long pipeline.

Historically, crude mixing occurred by blending the crude oils in one ormore tanks. Tank mixing is the most common form of crude mixing in theoil and gas industry. While relatively inexpensive, such methods haveseveral undesirable drawbacks. For example, the extent and/or accuracyof the mixing may be less precise (e.g., having an error rate of +/−about 10% based on a target set point). Such methods typically requirean entire tank to be dedicated to blending the crude oils along withseparate distribution piping therefrom. In addition, the mixed crudeproduct tends to stratify in the tank without the use of tank mixers,which also require additional capital investment. Further, the mixedcrude product is generally limited to a 50/50 blend ratio.

An alternative to tank mixing is parallel mixing, which uses two pumpsto pump two controlled feed streams (e.g., one pump per feed stream) ondemand from separate tanks and into the pipeline. While parallel mixingis typically more precise than tank mixing, it is also more difficult tocontrol because both streams are pumped by booster pumps into a commonstream. Typically, the two pumped streams are individually controlled byvariable speed pumps or pumps with flow control valves; therefore, thetwo sets of independent controls may interfere with each other and/ormay have difficulty reaching steady state if not programmed correctly.

Applicant has recognized, however, that in parallel mixing operations,both streams need to be boosted to about 50-200 psi of pressure in thetank farm to provide adequate suction pressure to a mainline boosterpump that is positioned downstream of the boosters. Even if one streamoperates at a fixed flow while the other varies, the need to boost thepressure of each stream to about 50-200 psi may require high horsepowerboost pumps dedicated to each line. Such dedicated pumps may be neededto supply streams at adequate pressure to the mainline pumps and mayrequire significant capital investment. From a commercial standpoint,for example, parallel mixing operations require much moreinfrastructure, representing a 180% to 200% increase in cost differencecompared to the in-line mixing systems disclosed herein. Therefore,there is a need in the industry for accurate and cost-effective blendingmethods and systems for crude and other hydrocarbon liquid products.

SUMMARY

The disclosure herein provides embodiments of systems and methods forin-line fluid mixing of hydrocarbon liquids. In particular, in one ormore embodiments, the disclosure provides in-line mixing systems thatmay be positioned at a tank farm, including at two or more sets of tankspositioned to each store one or more hydrocarbon liquids. Such anembodiment of an in-line mixing system is positioned to admix two ormore of those hydrocarbon liquids contained within the two or more setsof tanks to provide a blended mixture within a single pipeline. In someembodiments, the systems and methods of the disclosure may provide forin-line mixing of at least two hydrocarbon liquids, at least threehydrocarbon liquids, or more to form a blended fluid flow in a singlepipeline, e.g., which may be referred to herein as two-component blend,three-component blends, or a blend containing more than threehydrocarbon liquids.

In one or more embodiments, an in-line fluid mixing system may bepositioned at a tank farm to admix hydrocarbon liquids from a pluralityof tanks into a single pipeline. The in-line fluid mixing system maycomprise a first set of tanks positioned at a tank farm with at leastone tank containing a hydrocarbon fluid therein. Each tank in the firstset of tanks may be connected to and in fluid communication with a firstheader. The first header may be configured to transport a flow of one ormore hydrocarbon fluids from the first set of tanks as a first fluid.The system may include a second set of tanks positioned at the tank farmwith at least one tank containing a hydrocarbon fluid therein. Each tankin the second set of tanks may be connected to and in fluidcommunication with a second header. The second header may be configuredto transport a flow of one or more hydrocarbon fluids from the secondset of tanks as a second fluid. The system may include a first pumphaving an inlet and an outlet. The outlet of the first pump may beconnected to a first booster pipe. The inlet of the first pump may beconnected to the first header to increase pressure of hydrocarbon fluidflow therethrough. The system may include a first meter connected to thefirst booster pipe and configured to measure a first flow rate. Thesystem may include a first spillback pipe having a first connection tothe first booster pipe between the first meter and the first pump and asecond connection to the first header upstream of the first set oftanks. The first spillback pipe may include a first control valvedisposed therein. The first control valve may be configured to adjust aflow rate of hydrocarbon flow through the first spillback pipe betweenthe first booster pipe and the first header. The system may include asecond pump having an inlet and an outlet. The outlet of the second pumpmay be connected to a second booster pipe and the inlet of the secondpump may be connected to the second header to increase pressure ofhydrocarbon fluid flow therethrough. The system may include a secondspillback pipe having a first connection to the second booster pipedownstream of the second pump and a second connection to the secondheader upstream of the second set of tanks. The second spillback pipemay include a second control valve disposed therein, with the secondcontrol valve configured to adjust a flow rate of hydrocarbon flowthrough the second spillback pipe between the second booster pipe andthe second header. The system may include a blend pipe configured toadmix hydrocarbon fluid that flows from the first booster pipedownstream of the first meter with hydrocarbon fluid that flows from thesecond booster pipe downstream of the first connection of the secondspillback pipe in order to create a blend flow. The system may include ablend meter connected to the blend pipe that measures flow rate of theblend flow through the blend pipe.

Another embodiment may include a method of admixing hydrocarbon liquidsfrom a plurality of sets of tanks into a single pipeline to providein-line mixing thereof. The method may include initiating a blendingprocess. The blending process may include blending two or morehydrocarbon liquids over a period of time. At least one of the two ormore hydrocarbon liquids may be stored in a tank of a first set of tanksand at least another of the two or more hydrocarbon liquids being storedin a tank of a second set of tanks. Each tank of the first and secondsets of tanks may be connected, via one or more pipes, to a blend pipethat is configured to blend the two or more hydrocarbon liquids into ablended hydrocarbon liquid. The method may include determining a densityof each of the two or more hydrocarbon liquids to be blended during theblending process. Upon initiation of the blending process, the methodmay include determining a first flow rate of hydrocarbon liquids thatflow from the first set of tanks into the blend pipe. The method mayinclude determining a blend flow rate of the blended hydrocarbon liquidin the blend pipe. The method may include determining a second flow rateof hydrocarbon liquids that flow from the second set of tanks into theblend pipe. The method may include determining a first spillback flowrate of a flow of hydrocarbon liquids from the first set of tanks thatis recirculated in a first spillback loop positioned upstream of theblend pipe. The determining the first spillback flow rate may be basedon a function of density of the hydrocarbon liquids flowing from thefirst set of tanks, a differential pressure upstream and downstream of afirst flow control valve disposed in the first spillback loop, and oneor more control valve characteristics. The method may includedetermining a second spillback flow rate of a flow of hydrocarbonliquids from the second set of tanks that is recirculated in a secondspillback loop positioned upstream of the blend pipe. The determiningthe second spillback flow rate may be based on a function of density ofthe hydrocarbon liquids flowing from the second set of tanks, adifferential pressure upstream and downstream of a second flow controlvalve disposed in the second spillback loop, and one or more controlvalve characteristics. In response to a difference between a targetratio and a ratio of the first flow rate and the second flow rate, themethod may include determining ratio adjustments for the first flow raterelative to the second flow rate. The method may include adjusting thefirst flow control valve based on the ratio adjustments to modify thefirst spillback flow rate thereby adjusting the first flow rate to drivethe ratio towards the target ratio.

Another embodiment may include a controller for an in-line mixing systemfor admixing hydrocarbon liquids from a plurality of sets of tanks intoa single pipeline via spillback loops. The controller may include a userinterface input/output in signal communication with a user interface.The controller may be configured to, in relation to the user interface,receive a target blend ratio of a first liquid to a second liquid,receive a first density of the first liquid, and receive a seconddensity of the second liquid. The controller may include a first inputin signal communication with a first meter to measure a first flow rateof the first liquid. The first meter may be connected to a first pipethat is connected to a first set of tanks of a tank farm. One or moretanks of the first set of tanks may be configured to store the firstliquid of the first density and to transfer the first liquid from thefirst set of tanks through the first pipe. The controller may beconfigured to obtain the first flow rate from the first meter via thefirst input after initiation of the blending operation. The controllermay include a second input in signal communication with a blend meterconnected to a blend pipe to measure a blend flow rate of a blendedliquid with the blended liquid being the first liquid entering the blendpipe from the first set of tanks and the second liquid entering theblend pipe from a second set of tanks. The blend pipe may be connectedto the first set of tanks via the first pipe and to the second set oftanks via a second pipe. One or more tanks of the second set of tanksmay be configured to store the second liquid of the second density andto transfer the second liquid from the second set of tanks through thesecond pipe. The controller may be configured to obtain the blend flowrate from the blend meter via the second input after initiation of theblending operation. The controller may include a first input/output insignal communication with a first flow control device. The first flowcontrol device may be designed to adjust recirculation of the firstliquid via a first spillback pipe connected to the first pipe andpositioned upstream of the blend pipe, thereby modifying the first flowrate. The controller may be configured to, in relation to the firstinput/output and after initiation of the blending operation, determinewhether the first flow rate is to be modified based on at least two ofthe first flow rate, the blend flow rate, or the target blend ratio. Inresponse to a determination that the first flow rate is to be modified,the controller may adjust an open percentage of the first flow controlvalve that adjusts recirculation of the first liquid via the first spillback pipe, thereby modifying the first flow rate. The controller mayinclude a second input/output in signal communication with a second flowcontrol device. The second flow control device may be designed to adjustrecirculation of the second liquid via a second spillback pipe connectedto the second pipe and positioned upstream of the blend pipe. Thecontroller may be configured to, in relation to the second input/outputand after initiation of the blending operation, determine whether flowof the second liquid into the blend pipe is to be modified based on atleast two of the first flow rate, the blend flow rate, or the targetblend ratio. The controller may, in response to a determination thatflow of the second liquid into the blend pipe is to be modified, adjustthe open percentage of the second flow control valve that adjustsrecirculation of the second liquid via the second spill back pipe,thereby modifying flow of the second liquid into the blend pipe.

Another embodiment may include a method of admixing hydrocarbon liquidsfrom a plurality of sets of tanks into a single pipeline to providein-line mixing thereof. The method may include initiating a blendingprocess that includes blending two or more hydrocarbon liquids over aperiod of time. At least one of the two or more hydrocarbon liquids maybe stored in a tank of a first set of tanks. At least another of the twoor more hydrocarbon liquids may be stored in a tank of a second set oftanks. Each tank of the first and second sets of tanks may be connected,via one or more pipes, to a blend pipe. The blend pipe may be configuredto blend the two or more hydrocarbon liquids into a blended hydrocarbonliquid. The method may include determining a density of each of the twoor more hydrocarbon liquids to be blended during the blending process.Upon initiation of the blending process, the method may includedetermining a first flow rate of hydrocarbon liquids flowing from thefirst set of tanks into the blend pipe. The method may further includedetermining a blend flow rate of the blended hydrocarbon liquid in theblend pipe. The method may include determining a second flow rate ofhydrocarbon liquids flowing from the second set of tanks into the blendpipe. The method may include passing a first portion of hydrocarbonliquids from the first set of tanks through a first spillback looppositioned upstream of the blend pipe. An amount of the first portion ofhydrocarbon liquids may be controlled by a first flow control valvedisposed in the first spillback loop. The method may include passing asecond portion of hydrocarbon liquids from the second set of tanksthrough a second spillback loop positioned upstream of the blend pipe.An amount of the second portion of hydrocarbon liquids may be controlledby a second flow control valve disposed in the second spillback loop. Inresponse to a difference between a target ratio and a ratio of the firstflow rate and the second flow rate, the method may include determiningratio adjustments for the first flow rate relative to the second flowrate. The method may include adjusting the first flow control valvebased on the ratio adjustments to modify the amount of the first portionof hydrocarbon liquids thereby adjusting the first flow rate to drivethe ratio towards the target ratio.

Still other aspects and advantages of these embodiments and otherembodiments, are discussed in detail herein. Moreover, it is to beunderstood that both the foregoing information and the followingdetailed description provide merely illustrative examples of variousaspects and embodiments, and are intended to provide an overview orframework for understanding the nature and character of the claimedaspects and embodiments. Accordingly, these and other objects, alongwith advantages and features of the present disclosure herein disclosed,will become apparent through reference to the following description andthe accompanying drawings. Furthermore, it is to be understood that thefeatures of the various embodiments described herein are not mutuallyexclusive and may exist in various combinations and permutations.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the disclosure willbecome better understood with regard to the following descriptions,claims, and accompanying drawings. It is to be noted, however, that thedrawings illustrate only several embodiments of the disclosure and,therefore, are not to be considered limiting of the scope of thedisclosure.

FIG. 1 is a schematic diagram of a two-component in-line mixing systempositioned at a tank farm to admix two hydrocarbon liquids from separatetanks into a single pipeline according to an embodiment of thedisclosure.

FIG. 2 is a schematic diagram of a three-component in-line mixing systempositioned at a tank farm to admix three hydrocarbon liquids fromseparate tanks into a single pipeline according to an embodiment of thedisclosure.

FIG. 3 is a schematic diagram of a three-component in-line mixing systempositioned at a tank farm to admix three hydrocarbon liquids fromseparate tanks into a single pipeline according to an embodiment of thedisclosure.

FIG. 4 is a schematic diagram of a three-component in-line mixing systempositioned at a tank farm admix three hydrocarbon liquids from separatetanks into a single pipeline.

FIG. 5 is a schematic diagram of a control system on a single fluidline, the control system including tank output pipe, a pump, a mixingbooster pipe, a blended fluid pipe, a tank flow meter, a flow controlvalve, a recirculation pipe, and a one-way valve disposed in therecirculation pipe, according to an embodiment of the disclosure.

FIGS. 6A through 6B are schematic diagrams of a two-component in-linemixing system positioned at a tank farm to admix two hydrocarbon liquidsfrom separate tanks into a single pipeline according to an embodiment ofthe disclosure.

FIGS. 7A through 7B are schematic diagrams of a three-component in-linemixing system positioned at a tank farm to admix three hydrocarbonliquids from separate tanks into a single pipeline according to anembodiment of the disclosure.

FIGS. 8A through 8B are schematic diagrams of a multi-component in-linemixing system positioned at a tank farm to admix two or more hydrocarbonliquids from separate tanks into a single pipeline according to anembodiment of the disclosure.

FIG. 9 is a simplified diagram illustrating a control system formanaging a multi-component in-line mixing system according to anembodiment of the disclosure.

FIG. 10 is another simplified diagram illustrating a control system formanaging a multi-component in-line mixing system according to anembodiment of the disclosure.

FIG. 11 is another simplified diagram illustrating a control system formanaging a multi-component in-line mixing system according to anembodiment of the disclosure.

FIG. 12 is a flow diagram, implemented in a controller, for managing amulti-component in-line mixing system according to an embodiment of thedisclosure.

FIG. 13 is a flow diagram, implemented in a controller, for managing amulti-component in-line mixing system according to an embodiment of thedisclosure.

FIGS. 14A, 14B, 14C, and 14D are schematic diagrams of in-line mixingsystems positioned at a tank farm to admix two or more hydrocarbonliquids from separate tanks into a single pipeline according to anembodiment of the disclosure.

FIG. 15 is a schematic diagram of an in-line mixing system positioned ata tank farm to admix two or more hydrocarbon liquids from separate tanksinto a single pipeline according to an embodiment of the disclosure.

FIG. 16 is a simplified diagram illustrating a control system formanaging a multi-component in-line mixing system according to anembodiment of the disclosure.

FIG. 17 is a flow diagram, implemented in a controller, for managing amulti-component in-line mixing system according to an embodiment of thedisclosure.

DETAILED DESCRIPTION

So that the manner in which the features and advantages of theembodiments of the systems and methods disclosed herein, as well asothers that will become apparent, may be understood in more detail, amore particular description of embodiments of systems and methodsbriefly summarized above may be had by reference to the followingdetailed description of embodiments thereof, in which one or more arefurther illustrated in the appended drawings, which form a part of thisspecification. It is to be noted, however, that the drawings illustrateonly various embodiments of the systems and methods disclosed herein andare therefore not to be considered limiting of the scope of the systemsand methods disclosed herein as it may include other effectiveembodiments as well.

The present disclosure provides embodiments of systems and methods forin-line fluid mixing of hydrocarbon liquids. “Hydrocarbon liquids” asused herein, may refer to petroleum liquids, renewable liquids, andother hydrocarbon based liquids. “Petroleum liquids” as used herein, mayrefer to liquid products containing crude oil, petroleum products,and/or distillates or refinery intermediates. For example, crude oilcontains a combination of hydrocarbons having different boiling pointsthat exists as a viscous liquid in underground geological formations andat the surface. Petroleum products, for example, may be produced byprocessing crude oil and other liquids at petroleum refineries, byextracting liquid hydrocarbons at natural gas processing plants, and byproducing finished petroleum products at industrial facilities. Refineryintermediates, for example, may refer to any refinery hydrocarbon thatis not crude oil or a finished petroleum product (e.g., such asgasoline), including all refinery output from distillation (e.g.,distillates or distillation fractions) or from other conversion units.In some non-limiting embodiments of systems and methods, petroleumliquids may include heavy blend crude oil used at a pipeline originationstation. Heavy blend crude oil is typically characterized as having anAmerican Petroleum Institute (API) gravity of about 30 degrees or below.However, in other embodiments, the petroleum liquids may include lighterblend crude oils, for example, having an API gravity of greater than 30degrees. “Renewable liquids” as used herein, may refer to liquidproducts containing plant and/or animal derived feedstock. Further, therenewable liquids may be hydrocarbon based. For example, a renewableliquid may be a pyrolysis oil, oleaginous feedstock, biomass derivedfeedstock, or other liquids, as will be understood by those skilled inthe art. The API gravity of renewable liquids may vary depending on thetype of renewable liquid.

In particular, in one or more embodiments, the disclosure provides anin-line mixing system that may be positioned at a tank farm thatincludes a plurality of tanks configured to store one or morehydrocarbon liquids. Such an in-line mixing system may provide admixingof two or more of those hydrocarbon liquids contained within theplurality of tanks to provide a blended mixture within a singlepipeline. In some embodiments, the systems and methods of the disclosuremay provide for in-line mixing of at least two hydrocarbon liquids, atleast three hydrocarbon liquids, or more than three hydrocarbon liquidsto form a blended fluid flow in a single pipeline, e.g., which may bereferred to herein as two-component blends, three-component blends, or ablend containing more than three hydrocarbon liquids. Advantageously,in-line mixing operations (sometimes referred to as “series mixing”) mayutilize one or more controlled, tank output streams (e.g., controlledvia a low horsepower mixing booster pump and flow control valve) and agravity-fed stream, all of which are upstream of a common booster pumpused to pump a blended fluid stream through a pipeline. Further, thein-line mixing system may include sensors, disposed throughout the tankfarm, to determine density or gravity, allowing for the in-line mixingsystem to blend the hydrocarbon liquids according to a target blenddensity or gravity, providing a precisely blended fluid or liquidstream.

In some embodiments, the systems and methods as described herein mayprovide for in-line, on-demand, blending of crude oil, other hydrocarbonliquids, and/or renewable liquids at a pipeline origination station. Apipeline origination station is typically located at or near a tank farm(e.g., having a plurality of tanks containing hydrocarbon liquids). Thepipeline origination station includes extensive piping capable oftransporting the hydrocarbon liquids from each of the nearby tanks inthe tank farm to one or more mainline booster pumps, which raise thehydrocarbon liquids to very high pressures for passage through the longpipeline. A “tank farm” as used herein, refers to a plurality of tankspositioned in an area, each of the plurality of tanks configured to holdone or more hydrocarbon liquids therein. In some embodiments, theplurality of tanks may be positioned proximate to each other or theplurality of tanks may be spread out across a larger area. In someembodiments, the plurality of tanks may be positioned sequentially suchthat each tank is equally spaced apart. Generally, the number ofindividual tanks in a tank farm may vary based on the size of thepipeline origination station and/or based on the amount of hydrocarbonliquids being stored in that facility. For example, the tank farm mayinclude at least 2, at least 4, at least 6, at least 8, at least 10, atleast 12, or more individual tanks within the tank farm.

As noted above, typical pipeline origination stations require blendingof two or more different hydrocarbon liquids in a blending tank prior topumping the blended hydrocarbon liquids from the blending tank itself.However, the systems and methods of this disclosure advantageouslyprovide in-line, on-demand mixing directly in a pipe in the tank farmprior to the blended liquid being pumped to the pipeline. Such pipeblending may eliminate stratification of mixed oil in tanks and does notrequire the use of individual tank mixers in each of the tanks. Thesesystems and methods may also eliminate the need to mix the hydrocarbonliquids in one or more tanks before the hydrocarbon liquids are pumpedtherefrom, which advantageously allows for the changing of the blendon-demand and on-demand blending during operation of the pipelineorigination station. In some embodiments, for example, a separateblending tank in the tank farm is not necessary, and thus, one or moretanks in the tank farm previously used for blending may beneficially beused for storage of additional hydrocarbon liquids, which may also beblended in-line. Further, basing blending operations on gravitymeasurements may increase accuracy and precision of blending. While ablending operation constantly or continuously checking gravity andadjusting may produce a less accurate blend, due to the lagging natureof gravity adjustments versus flow rate, checking the gravity andadjusting flow rates at specified time intervals (for example, 10 to 20minute intervals) may allow for an accurate and precise blend. Further,adjusting while continuing a blending operation or process ensures anaccurate and precise blend, as well as a blend produced in the sameamount of time as a typical blending operation. Further still, suchgravity measuring and adjusting systems may include little additionalequipment (e.g., flow meters included in the tank farm may be Coriolismeters or density or gravity sensors may be added near the meter or to apipe or tank).

Other typical pipeline origination stations may use parallel mixing oftwo or more hydrocarbon liquids, which may be expensive and of lowerefficiency. In particular, typical parallel mixing operations require adedicated high horsepower mixing booster pump (e.g., greater than 750hp, greater than 850 hp, greater than 950 hp or even greater than 1050hp) for each of the mixing streams and an additional static mixer toblend the hydrocarbon liquids pumped through each of the mixing streams.However, the systems and methods of this disclosure advantageouslyprovide cost and energy savings, because such systems and methods do notrequire high horsepower mixing booster pumps or the additional staticmixer. For example, the mixing booster pumps typically used in themixing streams of the systems and methods described herein typicallyhave lower horsepower ratings (e.g., less than 250 hp, less than 200 hp,less than 150 hp, or even less than 100 hp). In addition, the in-linemixing systems, according to this disclosure, may eliminate the need fortwo or more variable speed pumps and/or control valves (i.e., one foreach of the streams), because as further disclosed herein, one streammay be gravity-fed from the tank and thus controls itself in physicalresponse to the other controlled, tank output stream(s). Further,in-line mixing systems as described herein may provide for more accuratecontrol of blended hydrocarbon liquids, for example, within 1.0 percentor less of the desired set point (e.g., desired flow rate and/or densityor gravity) for the blended fluid flow.

FIG. 1 depicts a process diagram of a non-limiting, two-componentin-line mixing system according to one or more embodiments of thedisclosure. In particular, FIG. 1 illustrates a two component in-linemixing system 100 positioned at a tank farm (e.g., as depicted by thedashed rectangular box in FIG. 1) to admix two hydrocarbon liquids fromseparate tanks into a single pipeline to provide a two-component blendedfluid flow. As shown in FIG. 1, the two-component in-line mixing systemincludes a first tank 102 (e.g., tank A) positioned in a tank farm andcontaining a first fluid therein. Generally, the first fluid includesone or more hydrocarbon liquids, of a first density or gravity, asdefined herein above and as would be understood by a person of skill inthe art. In some embodiments, the first tank 102 may have a first outputpipe 104 connected to the first tank 102 proximate a bottom portionthereof and the first output pipe 104 may be in fluid communication withthe first fluid to transport a flow of the first fluid from the firsttank 102 through the first output pipe 104 at a first pressure. In someembodiments, the first pressure may be in the range of about 0.1 poundper square inch (psi) to about 100 psi, about 0.5 psi to about 50 psi,or about 1 psi to about 10 psi. In some embodiments, the first pressuremay be less than about 20 psi, less than about 10 psi, less than about 5psi, or less than about 1 psi. In some embodiments, the first pressureresults from force of gravity on the first fluid contained in the firsttank. For example, gravity rather than a pump transports the flow of thefirst fluid from the first tank and through the first outlet pipe. Anoutlet pipe having a pressure that results from force of gravity, andnot by a pump, may be referred to herein as a “gravity-fed” line.

In one or more embodiments, the two-component in-line mixing system mayinclude a second tank 106 (e.g., tank C) positioned in the tank farm andcontaining a second fluid therein. Generally, the second fluid includesone or more hydrocarbon liquids, of a second density or gravity, asdefined herein above and as would be understood by a person of skill inthe art. In some embodiments, the second tank 106 may have a secondoutput pipe 108 connected to the second tank 106 proximate a bottomportion thereof and the second output pipe 108 may be in fluidcommunication with the second fluid to transport a flow of the secondfluid from the second tank 106 through the second output pipe 108 at asecond pressure. In some embodiments, the second pressure may be in therange of about 0.1 pound per square inch (psi) to about 100 psi, about0.5 psi to about 50 psi, or about 1 psi to about 10 psi. In someembodiments, the second pressure may be less than about 20 psi, lessthan about 10 psi, less than about 5 psi, or less than about 1 psi.Similar to the first pressure, the second pressure also results fromforce of gravity on the second fluid contained in the second tank. Forexample, gravity rather than a pump transports the flow of the secondfluid from the second tank and through the second outlet pipe.

In one or more embodiments, two-component in-line mixing systems asdescribed herein may include a first pump 110 having an inlet and anoutlet. For example, the inlet of the first pump 110 may be connected tothe second output pipe 108 to increase pressure of the flow of thesecond fluid from the second pressure to a pump pressure at the outlet.In some embodiments, the pump pressure at the outlet of the first pumpmay be in the range of about 1 psi to about 100 psi, about 10 psi toabout 50 psi, or about 25 psi to about 35 psi. In some embodiments, thepump pressure at the outlet of the first pump may be at least about 10psi, at least about 20 psi, at least about 30 psi, at least about 40psi, at least about 50 psi, or higher. Further, this first pump 110 mayhave a horsepower between 1 hp and 500 hp, between 50 and 250 hp orbetween 125 hp and 175 hp. In such embodiments, the first pump 110 mayhave a horsepower of 500 hp or less, 400 hp or less, 300 hp or less, 200hp or less, 100 hp or less, and lower. Generally, the pump pressure atthe outlet of the first pump is greater than the second pressure in thesecond output pipe. In some embodiments, in-line mixing systems asdescribed herein may include a variable speed drive (VFD) 132 connectedto the first pump 110 to control pump speed to thereby adjust the flowof the second fluid through the first pump. Generally, variable speeddrives, which may also be referred to as adjustable speed drives, aredevices that may vary the speed of a normally fixed speed motor and/orpump based on feedback from one or more control components. The specifictype of variable speed drive may vary as would be understood by a personof skill in the art.

As depicted in FIG. 1, in some embodiments, two-component in-line mixingsystems as described herein may include a mixing booster pipe 112connected to the outlet of the first pump 110 to transport the flow ofthe second fluid therethrough. In some embodiments, a blended fluid pipe114 may be connected to and in fluid communication with the first outputpipe 104 and the mixing booster pipe 112 to admix the flow of firstfluid at the first pressure and the flow of second fluid into a blendedfluid flow. In one or more embodiments, the pump pressure of the secondfluid may be about equal to pressure of the first fluid at the portionof the blended fluid pipe 114 configured to admix the flow of firstfluid and the flow of second fluid into a blended fluid flow. In someembodiments, a tank flow meter 116 may be connected to the mixingbooster pipe 112 and positioned between the first pump 110 and theblended fluid pipe 114 to measure flow rate of the flow of the secondfluid between the first pump 110 and the blended fluid pipe 114. Thetank flow meter 116 may be a turbine flow meter or another type of flowmeter as would be known to those skilled in the art. Generally, the tankflow meter may provide flow readings in the form of barrels per hour ofhydrocarbon liquids. In another embodiment the tank flow meter 116 mayinclude a sensor or functionality to measure a density or gravity of theliquid (e.g., a mass flow meter or other meter as will be understood bythose skilled in the art). In certain embodiments, a flow control valve118 may also be connected to the mixing booster pipe 112 between thetank flow meter 116 and the blended fluid pipe 114 to control flow ofthe second fluid between the first pump 110 and the blended fluid pipe114. In some embodiments, a pressure sensor/transducer 130 may also beconnected to the mixing booster pipe 112 and positioned upstream of theflow control valve 118. In some embodiments, for example, the pressuresensor/transducer 130 may be connected to the mixing booster pipe 112proximate the tank flow meter 116. The pressure sensor/transducer 130may be configured to measure the back pressure at the flow controlvalve. Any type of pressure sensor/transducer may be used to measure theback pressure at the flow control valve as would be understood by aperson of skill in the art.

In one or more embodiments, two-component in-line mixing systems asdescribed herein may include a second pump 120 having an inlet in fluidcommunication with the blended fluid pipe 114 and an outlet. Generally,the second pump 120 will have a greater horsepower than the first pump110 and thus, the pump pressure at the outlet of the second pump may begreater than the pump pressure at the outlet of the first pump as notedabove. In some embodiments, for example, the pump pressure at the outletof the second pump may be in the range of about 50 psi to about 500 psi,about 100 psi to about 300 psi, or about 150 psi to about 200 psi. Insome embodiments, the pump pressure at the outlet of the second pump maybe at least about 50 psi, at least about 100 psi, at least about 150psi, at least about 200 psi, or higher. Further, this second pump 120may have a horsepower between 250 hp and 2,500 hp, between 500 and 2,000hp or between 750 hp and 1,500 hp. In such embodiments, the second pump120 may have a horsepower of as much as 250 hp, 500 hp, 750 hp, 1,000hp, 1,250 hp, 1,500 hp or more. The second pump 120 is positionedrelative to the first pump 110 and the first tank 102 such that thepressure in the blended fluid pipe 114 at the inlet or suction of thesecond pump 120 is sufficiently high to preclude cavitation within thesecond pump 120. Generally, the pump pressure at the outlet of thesecond pump 120 is considerably higher than the pressure at the outletof the first pump 110 to ramp up the pressure of the blended fluid flowprior to transfer to the pipeline.

In some embodiments, two-component in-line mixing systems as describedherein may include a booster flow meter 122 in fluid communication withthe blended fluid pipe 114 to measure total flow rate of the blendedfluid flow transported through the blended fluid pipe 114. The boosterflow meter 122 may be a turbine flow meter or another type of flow meteras would be known to those skilled in the art. Generally, the boosterflow meter 122 may provide flow readings in the form of barrels per hourof hydrocarbon liquids. In another embodiment the booster flow meter 122may include a sensor or functionality to measure a density or gravity ofthe blended fluid or liquid (e.g., a mass flow meter or other meter aswill be understood by those skilled in the art). In some embodiments,the in-line mixing systems as described herein may include a pipeline124 connected to the outlet of the second pump 120 to transport theblended fluid flow therethrough and away from the tank farm, e.g., to apipeline origination station. In one or more embodiments, the in-linemixing systems described herein and shown in FIG. 1, may optionallyinclude a third pump 126 positioned between the outlet of the secondpump 120 and the pipeline 124. The third pump 126 is thus arranged to bein fluid communication with the outlet of the second pump 120, thebooster flow meter 122, and the pipeline 124. Generally, the third pump126 will have a greater horsepower and a greater outlet pump pressurethan either of the first pump 110 and the second pump 120 in order totransport the blended fluid flow at much higher pressures through thepipeline 124. Such higher pressures are generally required for pumpingthe blended fluid flow along long pipelines before reaching a finaldestination. For example, such pipelines may be in excess of hundreds ofmiles in length. In some embodiments, the pump pressure at the outlet ofthe optional third pump may be in the range of about 100 psi to about10,000 psi, about 500 psi to about 5,000 psi, or about 1,000 psi toabout 2,000 psi. In some embodiments, the pump pressure at the outlet ofthe third pump 126 may be at least about 500 psi, at least about 1,000psi, at least about 1,500 psi, or higher. Further, this third pump 126may have a horsepower between 1,000 hp and 5,000 hp, between 2,000 and4,500 hp or between 3,000 hp and 4,000 hp. In such embodiments, thethird pump 126 may have a horsepower of as much as 2,500 hp, 3,000 hp,3,500 hp, 4,500 hp, 5,000 hp or more. While the third pump 126 is shownin FIG. 1 as being within the tank farm (e.g. as depicted by the dashedrectangular box in FIG. 1), the third pump 126 (and start of thepipeline 124) may be located a distance apart from the tank farm, e.g.,less than one mile, less than two or less than three miles. However, thethird pump 126 is positioned relative to the second pump 120 such thatthe pressure at the inlet or suction of the third pump 126 issufficiently high to preclude cavitation within the third pump 126.

In one or more embodiments, in-line mixing systems as described hereinmay include one or more controllers 128 in communication with the tankflow meter 116, the booster flow meter 122, the pressuresensor/transducer 130, and the variable speed drive (VFD) 132.Generally, the one or more controllers 128 may perform a variety offunctions (e.g., determining mix ratios, flow rates, various densities,various gravities, corrected mix ratios, and/or controlling one or morefunctions of various components within the in-line mixing system 100).In some embodiments, the one or more controllers 128 may be configuredto determine a ratio of the flow of second fluid to the flow of firstfluid responsive to one or more signals received from the tank flowmeter 116 and the booster flow meter 122. For example, the booster flowmeter 122 may be configured to measure a total flow rate of the blendedfluid flow therethrough and the tank flow meter 116 may be configured tomeasure the flow rate of the flow of the second fluid therethrough, suchthat the difference in the total flow rate of the blended fluid flow andthe flow rate of the flow of the second fluid is approximately equal tothe flow rate of the flow of the first fluid (e.g., which isgravity-fed). In some embodiments, both of the tank flow meter 116 andthe booster flow meter 122 may provide flow readings in units of barrelsper hour of hydrocarbon liquids. For example, if the booster flow meter122 indicates that the blended flow has a flow rate of 10,000 barrelsper hour and the tank flow meter 116 indicates that the flow rate of theflow of the second fluid is 4,000 barrels per hour, then the calculatedflow rate of the flow of the first liquid is 6,000 barrels per hour(e.g., providing a mix ratio in the blended flow of approximately 40:60(second fluid:first fluid)). In some embodiments, the one or morecontrollers 128 may be in communication with each of the tank flow meter116 and the booster flow meter 122 to determine flow rate of the firstfluid from the first tank 102 responsive to signals received from thetank flow meter 116 and the booster flow meter 122. In some embodiments,the tank flow meter 116 and booster flow meter 122 may include othersensors or functionality to provide a density or gravity of the secondfluid (as well as the first fluid, in another example). If provided as agravity, the tank flow meter 116 and booster flow meter 122 may indicatethe gravity as a specific gravity. The one or more controllers 128 mayfurther determine a density or gravity of the first fluid, based on thedensities or gravities of the second fluid and blended fluid. Further,the controller 128 may adjust the flow rate of second flow, based on thedensities or gravities of the first fluid, the second fluid, and theblended fluid and the target blend density or gravity.

In such embodiments, the ratio of the flow of the second fluid to theflow of the first fluid may be referred to herein as the mix ratio ofthe blended fluid flow. In some embodiments, the mix ratio may be variedin the range of about 1:99 (second fluid:first fluid) to about 99:1(second fluid:first fluid). For example, in some embodiments, theblended fluid flow may include the flow of the second fluid in an amountof at least 5 percent, at least 10 percent, at least 15 percent, atleast 20 percent, at least 25 percent, at least 30 percent, at least 35percent, at least 40 percent, at least 45 percent, at least 50 percent,at least 55 percent, at least 60 percent, at least 65 percent, at least70 percent, at least 75 percent, at least 80 percent, at least 85percent, at least 90 percent, at least 95 percent, or more. In someembodiments, the blended fluid flow may include the flow of the firstfluid in an amount of at least 5 percent, at least 10 percent, at least15 percent, at least 20 percent, at least 25 percent, at least 30percent, at least 35 percent, at least 40 percent, at least 45 percent,at least 50 percent, at least 55 percent, at least 60 percent, at least65 percent, at least 70 percent, at least 75 percent, at least 80percent, at least 85 percent, at least 90 percent, at least 95 percent,or more.

As noted above, the mix ratio (also referred to as the blend ratio)generally refers to the ratio of the second fluid to the first fluid inthe total blended fluid flow. For example, a hypothetical blended fluidflow having a total flow rate of 10,000 barrels per hour with a mixratio of 60:40 (second fluid:first fluid) would equate to a second fluidflow rate of 6,000 barrels per hour and a first fluid flow rate of 4,000barrels per hour. Thus, the actual mix ratio may be constantlycalculated during operation of the in-line mixing system based onmeasurement of the individual flow rates of the flow of the second fluidand the flow of the first fluid. It should be noted that the actual mixratio will inherently fluctuate above and below a set point in acontrolled system (e.g., such as in-line mixing systems 100 as describedherein) based on control adjustments being made on-demand, in real-time.In addition, the amount of fluctuation in the actual mix ratio (e.g.,the variance in the mix ratio) may be higher at the beginning of ablending operation run (e.g., operation for 30 minutes or less, 20minutes or less, 10 minutes or less, or 5 minutes or less after a newset point mix ratio is input into the system) relative to a later timein the same blending operation run when steady state control has beenachieved (e.g., operation for 30 minutes or longer, 1 hour or longer, 2hours or longer, 4 hours or longer, 8 hours or longer, 12 hours orlonger, or 24 hours or longer after a new set point mix ratio is inputinto the system). Generally, longer blending operation runs may providebetter accuracy because steady state is reached within the in-linemixing system and this steady state is maintained for a longer period oftime. Advantageously, the systems and methods of in-line mixing asdescribed herein provide far more accurate control of the mix ratio(both at the beginning of a blending operation run and for the durationof the blending operation run) than typically provided with otherblending methods commonly used in the art. In-line mixing systems 100according to the disclosure may maintain the mix ratio within about+/−1.0 percent of the desired/pre-selected set point mix ratio. Incertain embodiments, in-line mixing systems according to the disclosuremay maintain the mix ratio within about +/−1.0 percent, about +/−0.5percent, about +/−0.25 percent, about +/−0.1 percent, or about +/−0.05percent of the desired/pre-selected set point mix ratio.

In one or more embodiments, the one or more controllers 128 may includea programmable logic controller. The one or more controllers 128 may bein communication with the variable speed drive 132, which may beconnected to the first pump 110, and configured to control the variablespeed drive 132. In such embodiments, the one or more controllers 128may be configured to compare the mix ratio to a pre-selected set pointratio and to determine a modified flow of the second fluid, ifnecessary, to bring the mix ratio closer to the pre-selected set pointratio. For example, the one or more controllers 128 may be configured tosend a control signal to the variable speed drive 132 to control thepump speed and thereby adjust the flow of the second fluid in order todrive the mix ratio toward the pre-selected set point ratio. If the mixratio is lower than the pre-selected set point ratio, then the flow ofthe second fluid may be increased to drive the mix ratio toward thepre-selected set point ratio. Likewise, if the mix ratio is higher thanthe pre-selected set point ratio, then the flow of the second fluid maybe decreased to drive the mix ratio toward the pre-selected set pointratio.

In one or more embodiments, the one or more controllers 128, e.g., aprogrammable logic controller, may be in communication with the flowcontrol valve 118 and configured to control the flow control valve. Forexample, in some embodiments, the one or more controllers 128 may governthe flow control valve 118 to maintain pressure at the tank flow meter116 between about 15 psi and about 25 psi. In at least one embodiment,the one or more controllers 128 may be configured to compare the mixratio to a pre-selected set point ratio to determine a modified flow ofthe second fluid. In some embodiments, the one or more controllers 128may be configured to send a control signal to the flow control valve 118to control the valve setting and thereby the flow of the second fluid inorder to drive the mix ratio toward the pre-selected set point ratio. Ifthe mix ratio is lower than the pre-selected set point ratio, then theflow control valve 118 may be opened to increase the flow of the secondfluid to drive the mix ratio toward the pre-selected set point ratio.Likewise, if the mix ratio is higher than the pre-selected set pointratio, then the flow control valve 118 may be pinched to reduce the flowof the second fluid to drive the mix ratio toward the pre-selected setpoint ratio.

In one or more embodiments of in-line mixing systems 100, the variablespeed drive (VFD) 132 and the flow control valve 118 may work togetherbased on input from the one or more controllers 128, including theprogrammable logic controller. In some embodiments, for example, whenthe speed of the first pump 110 drops below 60%, the programmable logiccontroller may send a signal to pinch the flow control valve 118 (e.g.,reducing the pressure at the output of the flow control valve by about 5psi) to force the first pump 110 to increase speed to maintain the mixratio. Likewise, if the speed of the first pump 110 increases to 100%,the programmable logic controller may send a signal to the flow controlvalve 118 to open the flow control valve 118 (e.g., increasing thepressure at the output of the flow control valve by about 5 psi) toforce the first pump 110 to decrease speed to maintain the mix ratio.Generally, the pressure at the flow control valve 118 is maintained atabout 20 psi when the in-line mixing system is maintained at steadystate.

As noted above, in one or more embodiments, the system and methodsdescribed herein may provide in-line mixing of three or more componentblends in a single pipe. For example, FIGS. 2-4 depict process diagramsof non-limiting, three-component in-line mixing system according tovarious embodiments of the disclosure. In particular, FIGS. 2-4illustrate embodiments, of three-component in-line mixing systems 200positioned at a tank farm (e.g., as depicted by the dashed rectangularboxes in FIGS. 2-4) to admix three hydrocarbon liquids from separatetanks into a single pipeline to provide a two-component blended fluidflow. As shown in FIGS. 2-4, a three-component in-line mixing system mayinclude a first tank 202 positioned in a tank farm and containing afirst fluid therein. Generally, the first fluid includes one or morehydrocarbon liquids, of a first density or gravity, as defined hereinabove and as would be understood by a person of skill in the art. Insome embodiments, the first tank may include a first output pipe 204connected to the first tank 202 proximate a bottom portion thereof andthe first output pipe 204 may be in fluid communication with the firstfluid to transport a flow of the first fluid from the first tank 202through the first output pipe 204 at a first pressure. In someembodiments, the first pressure may be in the range of about 0.1 psi toabout 100 psi, about 0.5 psi to about 50 psi, or about 1 psi to about 10psi. In some embodiments, the first pressure may be less than about 20psi, less than about 10 psi, less than about 5 psi, or less than about 1psi. In the embodiments depicted in FIGS. 2-4, the first pressureresults from force of gravity on the first fluid contained in the firsttank.

In one or more embodiments, the three-component in-line mixing systemmay include a second tank 206 positioned in the tank farm and containinga second fluid therein. Generally, the second fluid includes one or morehydrocarbon liquids, of a second density or gravity, as defined hereinabove and as would be understood by a person of skill in the art. Insome embodiments, the second tank 206 may include a second output pipe208 connected to the second tank 206 proximate a bottom portion thereofand the second output pipe 208 may be in fluid communication with thesecond fluid to transport a flow of the second fluid from the secondtank 206 through the second output pipe 208 at a second pressure. Insome embodiments, the second pressure may be in the range of about 0.1psi to about 100 psi, about 0.5 psi to about 50 psi, or about 1 psi toabout 10 psi. In some embodiments, the second pressure may be less thanabout 20 psi, less than about 10 psi, less than about 5 psi, or lessthan about 1 psi. Similar to the first pressure, the second pressurealso results from force of gravity on the second fluid contained in thesecond tank 206.

In one or more embodiments, the three-component in-line mixing systemmay include a third tank 210 positioned in the tank farm and containinga third fluid therein. Generally, the third fluid includes one or morehydrocarbon liquid, of a third density or gravity, as defined hereinabove and as would be understood by a person of skill in the art. Insome embodiments, the third tank 210 may include a third output pipe 212connected to the third tank 210 proximate a bottom portion thereof andthe third output pipe 212 may be in fluid communication with the thirdfluid to transport a flow of the third fluid from the third tank 210through the third output pipe 212 at a third pressure. In someembodiments, the third pressure may be in the range of about 0.1 psi toabout 100 psi, about 0.5 psi to about 50 psi, or about 1 psi to about 10psi. In some embodiments, the second pressure may be less than about 20psi, less than about 10 psi, less than about 5 psi, or less than about 1psi. Similar to the first and second pressures, the third pressure alsoresults from the force of gravity on the third fluid contained in thethird tank 210.

In one or more embodiments, three-component in-line mixing systems 200as described herein may include a second tank pump 214 having an inletand an outlet. For example, the inlet of the second tank pump 214 may beconnected to the second output pipe 208 to increase pressure of the flowof the second fluid from the second pressure to a second pump pressureat the outlet of the second tank pump 214. In some embodiments, thesecond pump pressure at the outlet of the second tank pump 214 may be inthe range of about 1 psi to about 100 psi, about 10 psi to about 50 psi,or about 25 psi to about 35 psi. In some embodiments, the second pumppressure at the outlet of the second tank pump 214 may be at least about10 psi, at least about 20 psi, at least about 30 psi, at least about 40psi, at least about 50 psi, or higher. Further, this second tank pump214 may have a horsepower between 1 hp and 500 hp, between 50 and 250 hpor between 125 hp and 175 hp. In such embodiments, the second tank pump214 may have a horsepower of 500 hp or less, 400 hp or less, 300 hp orless, 200 hp or less, 100 hp or less, and lower. Generally, the secondpump pressure at the outlet of the second tank pump 214 is greater thanthe second pressure in the second output pipe 208. In some embodiments,a second tank mixing booster pipe 216 may be connected to the outlet ofthe second tank pump 214 to transport the flow of the second fluidtherethrough. In some embodiments, three-component in-line mixingsystems 200 as described herein may include a second variable speeddrive 244 connected to the second tank pump 214 to control pump speed tothereby adjust the flow of the second fluid through the second tank pump214. The specific type and/or configuration of the second variable speeddrive 244 may vary as would be understood by a person of skill in theart.

In one or more embodiments, three-component in-line mixing systems 200as described herein may include a third tank pump 218 having an inletand an outlet. For example, the inlet of the third tank pump 218 may beconnected to the third output pipe 212 to increase pressure of the flowof the third fluid from the third pressure to a third pump pressure atthe outlet of the third tank pump 218. In some embodiments, the thirdpump pressure at the outlet of the third tank pump 218 may be in therange of about 1 psi to about 100 psi, about 10 psi to about 50 psi, orabout 25 psi to about 35 psi. In some embodiments, the third pumppressure at the outlet of the third tank pump 218 may be at least about10 psi, at least about 20 psi, at least about 30 psi, at least about 40psi, at least about 50 psi, or higher. Further, this third tank pump 218may have a horsepower between 1 hp and 500 hp, between 50 and 250 hp orbetween 125 hp and 175 hp. In such embodiments, the third tank pump 218may have a horsepower of 500 hp or less, 400 hp or less, 300 hp or less,200 hp or less, 100 hp or less, and lower. Generally, the third pumppressure at the outlet of the third tank pump 218 is greater than thethird pressure in the third output pipe 212. In some embodiments, athird tank mixing booster pipe 220 may be connected to the outlet of thethird tank pump 218 to transport the flow of the third fluidtherethrough. In some embodiments, three-component in-line mixingsystems 200 as described herein may include a third variable speed drive248 connected to the third tank pump 218 to control pump speed tothereby adjust the flow of the third fluid through the third tank pump218. The specific type and/or configuration of the third variable speeddrive 248 may vary as would be understood by a person of skill in theart.

As depicted in FIGS. 2-4, in some embodiments, three-component in-linemixing systems 200 may include a blended fluid pipe 222 connected to andin fluid communication with the first output pipe 204, the second tankmixing booster pipe 216, and the third tank mixing booster pipe 220 toadmix the flow of the first fluid at the first pressure, the flow of thesecond fluid, and the flow of the third fluid into a blended fluid flow.In some embodiments, the pressures of the third fluid, the second fluid,and the first fluid may be about the same at the portion of the blendedfluid pipe 222 configured to admix the flow of the first fluid, the flowof the second fluid, and the flow of the third fluid into the blendedfluid flow.

As noted in FIGS. 2-4, for example, the connection point between thefirst output pipe 204, the second tank mixing booster pipe 216, thethird tank mixing booster pipe 220, and the blended fluid pipe 222 mayvary in different embodiments. As depicted in FIG. 2, for example, theblended fluid pipe 222 may be directly in line with the first outputpipe 204 (i.e., the gravity fed output line) with the second tank mixingbooster pipe 216 and the third tank mixing booster pipe 220, or acombined pipe thereof, flowing into first output pipe/blended fluid pipejunction, e.g., through a tee joint or y joint. As depicted in FIG. 3,the blended fluid pipe 222 may be directly in line with the second tankmixing booster pipe 216 or, in another example, the third tank mixingbooster pipe 220 such that the first output pipe 204 is routed to flowinto the junction between the blended fluid pipe and the second tankmixing booster pipe 216 and/or third tank mixing booster pipe 220, e.g.,through a tee joint, y joint, or four-way joint. Further, as depicted inFIG. 4, any one of the plurality of tanks in the tank farm may beconfigurable to be a gravity fed line (e.g., such as the first outputpipe 204 in FIG. 2) or to be a controlled, tank output stream (e.g.,such as the second tank mixing booster pipe 216 or the third tank mixingbooster pipe 220 in FIG. 2). For example, the first tank 202 may beconfigured to be the gravity fed line or the third tank 210 may,instead, be configured as the gravity fed line. Likewise, the first tank202 or the third tank 210 may be configured to be a controlled, tankoutput stream. Such configurations and arrangements are not intended tobe limiting and are presented by way of example only. Generally, theconfiguration and/or arrangement of the first output pipe, the secondtank mixing booster pipe, the third tank mixing booster pipe, and theblended fluid pipe may vary based on the configuration of the tank farm.

Referring again to FIGS. 2-4, in some embodiments of three-componentin-line mixing systems 200 as described herein, a second tank flow meter224 may be connected to the second tank mixing booster pipe 216 andpositioned between the second tank pump 214 and the blended fluid pipe222 to measure flow rate of the flow of the second fluid between thesecond tank pump 214 and the blended fluid pipe 222. The second tankflow meter 224 may be a turbine flow meter or another type of flow meteras would be known to those skilled in the art. Generally, the boosterflow meter 234 may provide flow readings in the form of barrels per hourof hydrocarbon liquids. In another embodiment, the second tank flowmeter 224 may include a sensor or functionality to measure a density orgravity of the blended fluid or liquid (e.g., a mass flow meter or othermeter as will be understood by those skilled in the art). In someembodiments, a second tank flow control valve 226 may be connected tothe second tank mixing booster pipe 216 between the second tank flowmeter 224 and the blended fluid pipe 222 to control the flow of thesecond fluid between the second tank pump 214 and the blended fluid pipe222. In some embodiments, a second tank pressure sensor/transducer 242may also be connected to the second tank mixing booster pipe 216 andpositioned upstream of the second tank flow control valve 226. In someembodiments, for example, the second tank pressure sensor/transducer 242may be connected to the second tank mixing booster pipe 216 between thesecond tank flow meter 224 and the second tank flow control valve 226.The second tank pressure sensor/transducer 242 may be configured tomeasure the back pressure at the second tank flow control valve 226. Anytype of pressure sensor/transducer may be used to measure the backpressure at the second tank flow control valve 226 as would beunderstood by a person of skill in the art.

In some embodiments, three-component in-line mixing systems 200 asdescribed herein may include a third tank flow meter 228 connected tothe third tank mixing booster pipe 220 and positioned between the thirdtank pump 218 and the blended fluid pipe 222 to measure flow rate of theflow of the third fluid between the third tank pump 218 and the blendedfluid pipe 222. The third tank flow meter 228 may be a turbine flowmeter or another type of flow meter as would be known to those skilledin the art. Generally, the third tank flow meter 228 may provide flowreadings in the form of barrels per hour of hydrocarbon liquids. Inanother embodiment the third tank flow meter 228 may include a sensor orfunctionality to measure a density or gravity of the blended fluid orliquid (e.g., a mass flow meter or other meter as will be understood bythose skilled in the art). In some embodiments, a third tank flowcontrol valve 230 may be connected to the third tank mixing booster pipe220 between the third tank flow meter 228 and the blended fluid pipe 222to control the flow of the third fluid between the third tank pump 218and the blended fluid pipe 222. In some embodiments, a third tankpressure sensor/transducer 246 may also be connected to the third tankmixing booster pipe 220 and positioned upstream of the third tank flowcontrol valve 230. In some embodiments, for example, the third tankpressure sensor/transducer 246 may be connected to the third tank mixingbooster pipe 220 between the third tank flow meter 228 and the thirdtank flow control valve 230. The third tank pressure sensor/transducer246 may be configured to measure the back pressure at the third tankflow control valve 230. Any type of pressure sensor/transducer may beused to measure the back pressure at the third tank flow control valve230 as would be understood by a person of skill in the art.

In one or more embodiments, three-component in-line mixing systems 200and methods may include a booster pump 232 having an inlet in fluidcommunication with the blended fluid pipe 222 and an outlet. Generally,the booster pump 232 will have a greater horsepower than the second tankpump 214 and the third tank pump 218 and thus, the pump pressure at theoutlet of the booster pump 232 may be greater than the pump pressure atthe outlet of the second tank pump 214 and/or the third tank pump 218.In some embodiments, for example, the pump pressure at the outlet of thebooster pump 232 may be in the range of about 50 psi to about 500 psi,about 100 psi to about 300 psi, or about 150 psi to about 200 psi. Insome embodiments, the pump pressure at the outlet of the booster pump232 may be at least about 50 psi, at least about 100 psi, at least about150 psi, at least about 200 psi, or higher. Further, the booster pump232 may have a horsepower between 250 hp and 2,500 hp, between 500 and2,000 hp or between 750 hp and 1,500 hp. In such embodiments, thebooster pump 232 may have a horsepower of as much as 250 hp, 500 hp, 750hp, 1,000 hp, 1,250 hp, 1,500 hp or more. The booster pump 232 ispositioned relative to the second tank pump 214, the third tank pump 218and the first tank 202 such that the pressure in the blended fluid pipe222 at the inlet or suction of the booster pump 232 is sufficiently highto preclude cavitation within the booster pump 232. Generally, the pumppressure at the outlet of the booster pump 232 is considerably higherthan the pressure at the outlet of the second tank pump 214 and/or thethird tank pump 218 to ramp up the pressure of the blended fluid flowprior to transfer to the pipeline 236.

In some embodiments, three-component in-line mixing systems 200 asdescribed herein may include a booster flow meter 234 in fluidcommunication with the blended fluid pipe 222 to measure total flow rateof the blended fluid flow transported through the blended fluid pipe222. The booster flow meter 234 may be a turbine flow meter or anothertype of flow meter as would be known to those skilled in the art.Generally, the booster flow meter may provide flow readings in the formof barrels per hour of hydrocarbon liquids. In some embodiments, thethree-component in-line mixing systems 200 as described herein mayinclude a pipeline 236 connected to the outlet of the booster pump 232to transport the blended fluid flow therethrough and away from the tankfarm, e.g., to a pipeline origination station. In one or moreembodiments, the three-component in-line mixing systems 200 describedherein, and as shown in FIGS. 2-4, may include a pipeline originationstation pump 238 positioned between the outlet of the booster pump 232and the pipeline 236. The pipeline origination station pump 238 isarranged to be in fluid communication with the outlet of the boosterpump 232, the booster flow meter 234 and the pipeline 236. Generally,the pipeline origination station pump 238 may have a greater horsepowerand a greater outlet pump pressure than each of the second tank pump214, the third tank pump 218, and the booster pump 232 in order totransport the blended fluid flow at much higher pressures through thepipeline 236. Such higher pressures are generally required for pumpingthe blended fluid flow through long pipelines before reaching a finaldestination. For example, such pipelines may be in excess of hundreds ofmiles in length. In some embodiments, the pump pressure at the outlet ofthe pipeline origination station pump 238 may be in the range of about100 psi to about 10,000 psi, about 500 psi to about 5,000 psi, or about1,000 psi to about 2,000 psi. In some embodiments, the pump pressure atthe outlet of the second tank pump 214 and/or third tank pump 218 may beat least about 500 psi, at least about 1,000 psi, at least about 1,500psi, or higher. Further, the pipeline origination station pump 238 mayhave a horsepower between 1,000 hp and 5,000 hp, between 2,000 and 4,500hp or between 3,000 hp and 4,000 hp. In such embodiments, the pipelineorigination station pump 238 may have a horsepower of as much as 2,500hp, 3,000 hp, 3,500 hp, 4,500 hp, 5,000 hp or more. While the pipelineorigination station pump 238 is shown in FIGS. 2-4 as being within thetank farm (e.g. as depicted by the dashed rectangular box in FIGS. 2-4),the pipeline origination station pump 238 (and start of the pipeline236) may be located a distance apart from the tank farm, e.g., less thanone mile, less than two or less than three miles. However, the pipelineorigination station pump 238 may be positioned relative to the boosterpump 232 such that the pressure at the inlet or suction of the pipelineorigination station pump 238 is sufficiently high to preclude cavitationwithin the pipeline origination station pump 238.

In one or more embodiments, three-component in-line mixing systems 200as described herein may include one or more controllers 240 incommunication with the second tank flow meter 224, the third tank flowmeter 228, the booster flow meter 234, the second tank pressuresensor/transducer 242, the second variable speed drive 244, the thirdtank pressure sensor/transducer 246, and the third variable speed drive248. Generally, the one or more controllers 240 may perform a variety offunctions (e.g., determining mix ratios, flow rates, various densities,various gravities, corrected mix ratios, and/or controlling one or morefunctions of various components within the system). In some embodiments,the one or more controllers 240 may be configured to determinepercentages of the first fluid flow rate, the second fluid flow rate,and the third fluid flow rate in the total blended flow responsive toone or more signals received from the second tank flow meter 224, thethird tank flow meter 228, and the booster flow meter 234. For example,the booster flow meter 234 may be configured to measure a total flowrate of the blended fluid flow therethrough; the second tank flow meter224 may be configured to measure the flow rate of the flow of the secondfluid therethrough; and the third tank flow meter 228 may be configuredto measure the flow rate of the flow of the third fluid therethrough,such that the difference in the total flow rate of the blended fluidflow, the flow rate of the flow of the second fluid, and the flow rateof the flow of the third fluid is approximately equal to the flow rateof the flow of the first fluid (e.g., which is gravity-fed). In someembodiments, each of the second tank flow meter 224, the third tank flowmeter 228 and the booster flow meter 234 may provide flow readings inunits of barrels per hour of hydrocarbon liquids. For example, if thebooster flow meter 234 indicates that the blended fluid flow has a flowrate of 10,000 barrels per hour and the second tank flow meter 224indicates that the flow rate of second fluid flow is 4,000 barrels perhour and the third tank flow meter 228 indicates that the flow rate ofthe third fluid flow is 5,000 barrels per hour, then the calculated flowrate of the first fluid flow is 1,000 barrels per hour (e.g., providingmix percentages in the blended flow of 50/40/10 (third fluid:secondfluid:first fluid)). In some embodiments, the one or more controllers240 may be in communication with each of the second tank flow meter 224,the third tank flow meter 228, and the booster flow meter 234 todetermine flow rate of the first fluid from the first tank 202responsive to signals received from the second tank flow meter 224,third tank flow meter 228, and the booster flow meter 234.

In some embodiments, the percentages of the third fluid flow to thesecond fluid flow to the first fluid flow may be referred to herein asthe mix percentages of the blended fluid flow. In some embodiments, themix percentages may be varied in the range of about 1 percent to about98 percent for each of the first fluid flow, the second fluid flow, andthe third fluid flow. For example, in some embodiments, the blendedfluid flow may include the first fluid flow in an amount of at least 5percent, at least 10 percent, at least 15 percent, at least 20 percent,at least 25 percent, at least 30 percent, at least 35 percent, at least40 percent, at least 45 percent, at least 50 percent, at least 55percent, at least 60 percent, at least 65 percent, at least 70 percent,at least 75 percent, at least 80 percent, at least 85 percent, at least90 percent, at least 95 percent, or more. In some embodiments, theblended fluid flow may include the second fluid flow in an amount of atleast 5 percent, at least 10 percent, at least 15 percent, at least 20percent, at least 25 percent, at least 30 percent, at least 35 percent,at least 40 percent, at least 45 percent, at least 50 percent, at least55 percent, at least 60 percent, at least 65 percent, at least 70percent, at least 75 percent, at least 80 percent, at least 85 percent,at least 90 percent, at least 95 percent, or more. In some embodiments,the blended fluid flow may include the third fluid flow in an amount ofat least 5 percent, at least 10 percent, at least 15 percent, at least20 percent, at least 25 percent, at least 30 percent, at least 35percent, at least 40 percent, at least 45 percent, at least 50 percent,at least 55 percent, at least 60 percent, at least 65 percent, at least70 percent, at least 75 percent, at least 80 percent, at least 85percent, at least 90 percent, at least 95 percent, or more. In someembodiments, the percentages of the third fluid flow to the second fluidflow to the first fluid flow may be referred to in terms of a percentagemix ratio. For example, in some embodiments, the percentage mix ratiomay be about 50:49:1 (third fluid:second fluid:first fluid). In otherembodiments, the percentage mix ratio may be about 50:46:4 (thirdfluid:second fluid:first fluid). Generally, the percentage mix ratio maybe varied such that any of the fluid flows are provided in amountbetween about 1 percent and about 98 percent of the total blended flow.

Advantageously, the systems and methods of in-line mixing as describedherein provide far more accurate control of the mix ratio (both at thebeginning of a blending operation run and for the duration of theblending operation run) than typically provided with other blendingmethods commonly used in the art. For example, in-line mixing systemsand methods according to the disclosure may maintain the mix percentageswithin about +/−1.0 percent of the desired/pre-selected set pointpercentages. In some embodiments, in-line mixing systems and methodsaccording to the disclosure may maintain the mix percentages withinabout +/−1.0 percent, about +/−0.5 percent, about +/−0.25 percent, about+/−0.1 percent, or about +/−0.05 percent of the desired/pre-selected setpoint percentages.

In at least one embodiment, the one or more controllers 240 may includea programmable logic controller. The one or more controllers 240 may bein communication with one or more variable speed drives (e.g., connectedto the second tank pump 214 and/or to the third tank pump 218) andconfigured to control the variable speed drives. In some embodiments,for example, in-line mixing systems and methods of the disclosure mayinclude a second variable speed drive 244 connected to the second tankpump 214 and a third variable speed drive 248 connected to the thirdtank pump 218. In such embodiments, the one or more controllers 240 maybe configured to compare the mix percentages to a pre-selected set pointpercentages and to determine a modified flow of one or both of thesecond fluid flow and the third fluid flow, if necessary, to bring themix percentages closer to the pre-selected set point percentages. Forexample, the one or more controllers 240 may be configured to send acontrol signal to at least one of the second variable speed drive 244and the third variable speed drive 248 to control the pump speed of thesecond tank pump 214 and/or third tank pump 218, respectively, andthereby adjust the flow of at least one of the second fluid and thethird fluid in order to drive the mix percentages toward thepre-selected set point percentages.

In one or more embodiments, the one or more controllers 240 may be incommunication with second tank flow meter 224, third tank flow meter228, and booster flow meter 234. The one or more controllers 240 mayobtain or determine a density or gravity for each liquid flowing throughsecond tank flow meter 224, third tank flow meter 228, and booster flowmeter 234. In such examples, the one or more controllers 240 may includea target blend density or gravity or a preset blend density or gravity.Such a target blend density or gravity may indicate the desired ortarget density or gravity of the blended fluid. As is illustrated inFIGS. 2-4, a meter may not be associated with the first tank 202. Inother words, the density or gravity may not be measured for the firsttank 202. Further, the one or more controllers 240 may determine thefirst density or gravity of the first liquid, based on the seconddensity or gravity (obtained or determined via second tank flow meter224), the third density or gravity (obtained or determined via thirdtank flow meter 228), and the blend density or gravity (obtained ordetermined via booster flow meter 234). Once all densities or gravitiesare available, the one or more controllers 240 may compare the blenddensity or gravity with the target blend density or gravity. Based ondifferences of such comparisons, the one or more controllers 240 maydetermine a corrected mix ratio. The one or more controllers 240 mayadjust the flow, based on the corrected mix ratio, of at least one ofthe second fluid and the third fluid, via the second variable speeddrive 244 and the third variable speed drive 248 and/or second tank flowcontrol valve 226 and the third tank flow control valve 230, in order todrive the blend density or gravity toward the target or preset blenddensity or gravity.

In one or more embodiments, the one or more controllers 240, e.g., aprogrammable logic controller, may be in communication with one or bothof the second tank flow control valve 226 and the third tank flowcontrol valve 230, and configured to control one or both of the secondtank flow control valve 226 and the third tank flow control valve 230.For example, in some embodiments, the one or more controllers 240 maygovern the second tank flow control valve 226 and the third tank flowcontrol valve 230 to maintain pressure at each of the second tank flowmeter 224 and the third tank flow meter 228 between about 15 psi andabout 25 psi. In at least one embodiment, the one or more controllers240 may be configured to compare the mix percentages to pre-selected setpoint percentages to determine a modified flow of one or both of thesecond fluid and the third fluid. In some embodiments, the one or morecontrollers 240 may be configured to send a control signal to at leastone of the second tank flow control valve 226 and the third tank flowcontrol valve 230 to control the respective valve setting and therebythe flow of second fluid and third fluid, respectively, in order todrive the mix percentages toward the pre-selected set point percentages.

In one or more embodiments of in-line mixing systems, the secondvariable speed drive 244 and the second tank flow control valve 226 maywork together based on input from the one or more controllers 240,including the programmable logic controller. In some embodiments, thethird variable speed drive 248 and the third tank flow control valve 230may work together based on input from the one or more controllers 240,including the programmable logic controller. In some embodiments, forexample, when the speed of the second tank pump 214 and/or the thirdtank pump 218 drops below 60%, the programmable logic controller maysend a signal to pinch the second tank flow control valve 226 and/or thethird tank flow control valve 230 (e.g., reducing the pressure at theoutput of the flow control valve by about 5 psi), respectively, to forcethe second tank pump and/or the third tank pump to increase speed tomaintain the desired mix percentages. Likewise, if the speed of thesecond tank pump 214 and/or the third tank pump 218 increases to 100%,the programmable logic controller may send a signal to open the secondtank flow control valve 226 and/or the third tank flow control valve 230(e.g., increasing the pressure at the output of the flow control valveby about 5 psi), respectively, to force the second tank pump 214 and/orthe third tank pump 218 to decrease speed to maintain the desired mixpercentages. Generally, the pressure at both the second tank flowcontrol valve 226 and the third tank flow control valve 230 ismaintained at about 20 psi when the in-line mixing system is maintainedat steady state.

FIG. 5 depicts a process diagram of a controlled, tank output stream 300having a recirculation loop or spillback loop, the controlled outputstream includes a recirculation pipe 302, and a one-way valve 304disposed in the recirculation pipe, a mixing booster pipe 306, a pump308, an output pipe 310, a tank flow meter 312, and a flow control valve314. As depicted in FIG. 5, the controlled, tank output stream line mayinclude an end portion 302 a of a recirculation pipe 302 connected toand in fluid communication with a mixing booster pipe 306 downstream ofa pump 308 and another end portion 302B of the recirculation pipe 302connected to and in fluid communication with an output pipe 310. Thus,the recirculation pipe 302 is arranged to recirculate a fluidtherethrough in order to maintain a minimum flow of the fluid throughthe pump 308. In some embodiments, the recirculation loop may include aone-way valve 304 disposed in the recirculation pipe 302 to prevent flowof the fluid from the output pipe to the mixing booster pipe 306.

A recirculation loop as depicted in FIG. 5 (e.g., including arecirculation pipe 302 and a one-way valve 304 disposed in therecirculation pipe 302) may be used in combination with any of thecontrolled, tank output streams in the systems described herein above(e.g., such as those depicted in FIGS. 1-4). In such embodiments, therecirculation pipe 302 may be positioned proximate to the pump 308connected to the tank output pipe in the controlled, tank output streams(e.g., such as the second output pipe 108 in FIG. 1 and/or the secondoutput pipe 208 in FIGS. 2-4 and/or the third output pipe 212 in FIGS.2-4). In FIG. 1, for example, a recirculation pipe 302 and a one-wayvalve 304 disposed in the recirculation pipe 302 may be positionedproximate to first pump 110 to provide a recirculation system having thesame components depicted in FIG. 5. In such embodiments, therecirculation pipe 302 may be configured to permit flow therethroughonly when a ratio of the flow of second fluid to the flow of first fluidfalls below a pre-selected threshold. In FIGS. 2-4, for example, arecirculation pipe 302 and a one-way valve 304 disposed in therecirculation pipe 302 may be positioned proximate one or both of secondtank pump 214 and third tank pump 218 to provide a recirculation systemhaving the same components depicted in FIG. 5. In such embodiments, therecirculation pipe 302 may be configured to permit flow therethroughwhen the flow of the second fluid is below a pre-selected percentage(e.g., when the recirculation pipe 302 is positioned proximate secondpump tank 214) and/or configured to permit flow therethrough when theflow of the third fluid is below a pre-selected percentage (e.g., whenthe recirculation pipe 302 is positioned proximate third pump tank 218).

In one or more embodiments, in-line mixing systems and methods accordingto the disclosure may include a recirculation loop in each of thecontrolled, tank output streams. In such embodiments, the one-way valve304 disposed in the recirculation pipe 302 may be in communication withone or more control components as described herein above. In someembodiments, if the flow control valve 314 holds a back pressure thatexceeds a pre-selected setting (as determined by a pressuresensor/transducer 316 positioned upstream of the flow control valve 314)and the pump 308 falls at or below 60 percent operational capacity orthroughput, the one or more controllers will send a signal to theone-way valve 304 to open the one-way valve 304. The pump 308 then pumpsfluid through the recirculation pipe 302 via the open one-way valve 304and back to the suction inlet of the pump 308, which increases fluidflow through the pump 308. Accordingly, the pump 308 is permitted tooperate at greater than 60% throughout even while the flow control valve314 holds a back pressure exceeding the pre-selected setting. Once theback pressure drops below a pre-selected value (as determined by thepressure sensor/transducer 316 positioned upstream of the valve), whichcorresponds to the valve opening to permit greater fluid flowtherethrough, the one or more controllers will send a signal to theone-way valve to close. Advantageously, these three components (i.e.,the variable speed pump, the flow control valve, and the recirculationloop) may work together to prevent damage (e.g., cavitation) to the pumpby maintaining an acceptable flow rate through the pump at all times.

Some aspects of the disclosure relate to methods of admixing hydrocarbonliquids (such as those described herein above) from a plurality of tanksinto a single pipeline, e.g., using one or more system embodimentsherein, to provide in-line mixing thereof. As noted herein above, thesystems and methods described herein are intended to be suitable forproviding mixing of two or more hydrocarbon liquids in-line, e.g., toprovide two-component blended flows, three-component blended flows, orblended flows having more than three components.

In one or more embodiments, for example, methods for admixing twohydrocarbon liquids from a plurality of tanks into a single pipeline mayinclude determining a ratio of a second fluid flow to a first fluid flowbased on signals received from a tank flow meter in fluid communicationwith the second fluid flow and a booster flow meter in fluidcommunication with a blended fluid flow. In such embodiments, theblended fluid flow may include a blended flow of the first fluid flowand the second fluid flow. In one or more embodiments, the methodsdescribed herein may include comparing the determined ratio to apre-selected set point ratio to thereby determine a modified flow of thesecond fluid flow in order to drive the ratio toward the pre-selectedset point ratio. In some embodiments, the methods described herein mayinclude controlling a variable speed drive connected to a pump tothereby control the second fluid flow through the pump based on thedetermined modified flow.

In some embodiments, one or more methods as described herein may includemaintaining the difference between the determined ratio and thepre-selected set point ratio within a pre-selected error range. Forexample, the pre-selected error range may be in the range of about 1.0%to −1.0%, about 0.5% to about −0.5%, about 0.25% to about −0.25%, about0.1% to about −0.1%, or about 0.05% to about −0.05%, based on thepre-selected set point.

In some embodiments, one or more methods as described herein may includedetermining a flow rate of the first fluid flow, which is gravity-fed,based on the signals received from the tank flow meter and the boosterflow meter. In some embodiments, the pressure of the first fluid flowmay be about equal to pressure of the second fluid flow at the junctionof the blended fluid pipe. In some embodiments, one or more methods asdescribed herein may include controlling a flow control valve in fluidcommunication with the second fluid flow to thereby control the secondfluid flow based on the determined modified flow. In some embodiments,one or more methods may include controlling a flow control valve influid communication with the second fluid flow to thereby maintainpressure at the tank flow meter between about 15 psi and about 25 psi.

In one or more embodiments, for example, methods for admixing threehydrocarbon liquids from a plurality of tanks into a single pipeline mayinclude determining percentages of flow rates of a first fluid flow, asecond fluid flow, and a third fluid flow in a blended fluid flow basedon signals received from a second tank flow meter in fluid communicationwith the second fluid flow, a third tank flow meter in fluidcommunication with the third fluid flow, and a booster flow meter influid communication with the blended fluid flow. In such embodiments,the blended fluid flow may include a blended flow of the first fluidflow, the second fluid flow, and the third fluid flow. In someembodiments, such methods may include comparing the determinedpercentages to pre-selected percentages to thereby determine modifiedflows of the second fluid and the third fluid in order to drive thedetermined percentages toward the pre-selected percentages. In someembodiments, such methods may include controlling at least one of asecond variable speed drive connected to a second pump and a thirdvariable speed drive connected to a third pump to thereby control atleast one of the second fluid flow and the third fluid flow based on thedetermined modified flows.

In some embodiments, one or more methods as described herein may includemaintaining the difference between the determined percentages and thepre-selected percentages within a pre-selected error range. For example,in some embodiments, the pre-selected error range may be in the range ofabout 1.0% to −1.0%, about 0.5% to about −0.5%, about 0.25% to about−0.25%, about 0.1% to about −0.1%, or about 0.05% to about −0.05%, basedon the pre-selected percentages.

In some embodiments, one or more methods as described herein may includedetermining a flow rate of the flow of the first fluid based on thesignals received from the second tank flow meter, the third tank flowmeter, and the booster flow meter. In some embodiments, pressures of thefirst fluid flow, second fluid flow, and third fluid flow may be aboutthe same at the junction of blended fluid pipe. In some embodiments, oneor more methods as described herein may include controlling at least oneof a second flow control valve in fluid communication with the secondfluid flow and a third flow control valve in fluid communication withthe third fluid flow to thereby control at least one of the second fluidflow and the third fluid flow based on the determined modified flows. Insome embodiments, one or more methods as described herein may includecontrolling a second flow control valve in fluid communication with thesecond fluid flow and a third flow control valve in fluid communicationwith the third fluid flow to thereby maintain pressure at each of thesecond tank flow meter and the third tank flow meter between about 15psi and about 25 psi.

FIGS. 6A through 6B are schematic diagrams of a two-component in-linemixing system positioned at a tank farm to admix two hydrocarbon liquidsfrom separate tanks into a single pipeline according to an embodiment ofthe disclosure. The in-line mixing system 600 may include two tanks(e.g., tank A 618 and tank B 620), three tanks, or more tanks, as notedabove. Tank A 618 may store a less dense or denser liquid than that ofthe liquid stored in tank B 620, depending on the final blend (in otherwords, Tank A 618 may store a liquid of a different density than that oftank B 620). Each tank (e.g., tank A 618 and tank B 620) may include orbe connected to and in fluid communication with output pipes (e.g., afirst output pipe 614 and a second output pipe 616, respectively).Output pipe 614 may attach directly to a blend pipe 612. The flow ofliquid stored in tank A 618 through the output pipe 614 may be gravitybased or gravity-fed, as described above. Such a flow may be affected bythe diameter of the output pipe 614 (e.g., smaller diameter pipes mayincrease pressure while decreasing flow and larger diameter pipes maydecrease pressure while increasing flow). In an embodiment, output pipe616 may be connected to and in fluid communication with a flow controldevice 608 (also referred to as a mechanical flow controller, a flowcontrol apparatus, and/or flow control subsystem). In an example, asensor 604 may be connected to and/or in fluid communication with eitherthe output pipe 616, the flow control device 608, or tank 620. Further,the flow control device 608 may include sensors (e.g., the sensorsincluding the functionality of sensor 604 and/or other functionality,such as the capability to provide a flow rate, pressure, and/or othervariables of the in-line mixing system 600). The flow control device 608may further be connected to and in fluid communication with a mixingpipe 613. The mixing pipe 613 and first output pipe 614 may be connectedto and in fluid communication with a blend pipe 612. The blend pipe 612may admix or mix the liquid flowing from tank A 618 and tank B 620(e.g., a first liquid and second liquid, respectively) during a blendingoperation. A sensor 602, as illustrated in FIG. 6B, may be connected toand/or in fluid communication with the output pipe 614. A sensor 610 maybe connected to and/or in fluid communication with the blend pipe 612.The sensor 602 and sensor 610 may be the same type of sensor as sensor604.

In an example, a blending or mixing process or operation may include twoor more liquids (e.g., the liquid stored in tank A 618 and tank B 620).The two or more liquids may be hydrocarbon liquids (e.g., petroleumliquids and/or renewable liquids). The density or gravity may or may notbe known based on various configurations of the tank farm. For example,upon delivery of a liquid, a user may receive the density or gravity oran estimate density or gravity, based on the type of liquid and/or on aform or ticket. In another example, the liquid delivered to a tank maybe of a certain type (i.e., heavy blend crude oil, light blend crudeoil, other types of hydrocarbon liquids, and/or renewable liquids) andmay be associated with an estimated density or gravity (e.g., for aheavy blend crude oil an API of about 30 degrees or less and for a lightblend crude oil an API of higher than 30 degrees). In another example,one density or gravity may be unknown (e.g., a particular tank or pipemay not include a sensor or meter, such as tank A 618 or output pipe 614in FIG. 6A), while all or some other densities or gravities may be knownor measured based on various sensors or meters disposed throughout thein-line mixing system 600 (e.g., sensor 604). In another example, when adensity or gravity is unknown, a sensor or meter (e.g., sensor 602and/or sensor 604 and sensor 610) may be utilized to determine anotherdensity or gravity and, based on the other density or gravity (forexample, the density or gravity of the second liquid and the blendliquid), the controller 606 may determine the unknown density orgravity. Such sensors or meters may be in signal communication with thecontroller 606. As noted, approximate, but inexact, densities orgravities may be known. In another example, the densities or gravitiesof all liquids to be blended may be measured via sensors or meters.

As used herein, “signal communication” refers to electric communicationsuch as hard wiring two components together or wireless communication,as understood by those skilled in the art. For example, wirelesscommunication may be Wi-Fi®, Bluetooth®, ZigBee, forms of near fieldcommunications, or other wireless communication methods as will beunderstood by those skilled in the art. In addition, signalcommunication may include one or more intermediate controllers, relays,or switches disposed between elements that are in signal communicationwith one another.

In an example, the sensors (e.g., sensor 602, sensor 604, and othersensors as will be described below) may be hydrometers, gravitometers,densitometers, density measuring sensors, gravity measuring sensors,pressure transducers, flow meters, mass flow meters, Coriolis meters,other measurement sensors to determine a density, gravity, or othervariable as will be understood by those skilled in the art, or somecombination thereof. In such examples, the sensors may measure thedensity and/or gravity of a liquid, the flow of the liquid, and/or thepressure of the liquid. As noted above, the controller 606 may be insignal communication with the sensors or meters. The controller 606 maypoll or request data from the sensors at various points in a blendingoperation. While a variety of sensors may be utilized, a hydrometer maybe preferred as, typically, hydrocarbon products are characterized byAPI gravity and a hydrometer may measure the specific gravity of aliquid. Thus, the controller 606 may convert an input API gravity onceto specific gravity for further determinations and/or calculations. Amass flow meter or Coriolis meter may also be preferred, as such metersmay measure flow and density. While such meters may potentially requireconversion of density to gravity, the use of such meters may reduce thetotal amount of equipment to use. Further, the sensor or meter may be influid communication with a liquid to measure the density or gravity ormay indirectly measure density or gravity (e.g., an ultrasonic sensor).In other words, the sensor or meter may be a clamp-on device to measureflow and/or density indirectly (such as via ultrasound passed throughthe pipe to the liquid).

As noted above, the sensors (sensor 602, sensor 604, and other) maymeasure the density or gravity of a liquid and/or a user may enter orthe controller 606 may store a density or gravity. The controller 606may be configured to perform the determination or calculations describedherein based on either density, gravity, specific gravity, or APIgravity. The controller 606 may be configured to convert any givenmeasurement based on the type of determinations or calculations (e.g.,determinations or calculations based on density, gravity, specificgravity, or API gravity). For example, a user may enter an API gravityfor a liquid at a user interface in signal communication with thecontroller. 606. The controller 606, may convert the entered API gravityto a specific gravity. In such examples, the sensors disposed throughoutthe system may measure the gravity of other liquids. In another example,the sensors may provide different measurements, e.g., density, and thecontroller 606 may further convert those measurements to gravity. Inanother example, the controller 606 may convert the entered API gravityto density. In such examples, the sensors disposed throughout the systemmay measure the density of other liquids. In another example, thesensors may provide different measurements, e.g., gravity, and thecontroller 606 may further convert those measurements to density.

As noted, the in-line mixing system 600 may perform various blending ormixing operations or processes. Rather than base control of the flowcontrol device 608 on just the flow and/or mix ratio of the liquids tobe blended, the in-line mixing system 600 may base control of the flowcontrol device 608 on the density or gravity of the liquids to beblended and a target blend density or gravity (in other words, thetarget density or gravity, being a density or gravity that may be soughtor desired for the final blend, may be utilized, rather than utilizationof just a mix ratio and/or flow of liquids to be blended). As noted,various liquids may be blended via the blend pipe 612. Further, one ormore densities or gravities of liquids to be blended (e.g., the densityor gravity of liquid stored in tank B 620) may be known or measured andanother unknown (e.g., the density or gravity of liquid stored in tank A618). As the blending or mixing operation or process starts, thecontroller 606 may determine or obtain a density or gravity from anyavailable sensors of the in-line mixing system 600 (e.g., from sensor604, sensor 610, and, if available, sensor 602) or from an input (e.g.,via a user interface). Based on the density or gravity obtained from thesensors (e.g., sensor 604 and sensor 610), the controller 606 maydetermine the density or gravity of the liquid of unknown density. Asnoted, sensors (e.g., sensor 604, sensor 610, and, if present, sensor602) may be disposed throughout the in-line mixing system 600 orincluded in flow control devices to measure all densities.

In the blending or mixing operation or process, a blend may be blendedto a target blend density or gravity. In other words, the blending ormixing operation or process may be based on a target blend density orgravity. A target blend density or gravity may be set or preset (inother words, loaded into or stored in) in the controller 606. The targetblend density or gravity may be set via a user interface in signalcommunication with the controller 606. For example, a user may set thetarget blend density or gravity at the user interface and the userinterface may send or transmit the target blend density or gravity tothe controller 606. In another example, the target blend density orgravity may be determined based on a particular or specified end productor blend. For example, a blending or mixing operation or process may beset to blend a high-volatile bituminous mixture or blend. In such ablend, an ideal or target blend density or gravity may be an API gravityof about 30 degrees. In such examples, the end product or blend (e.g.,the high-volatile bituminous mixture or blend) API gravity may beincluded in or preset in the controller 606. In another example, a userinterface may include a selectable list of various options for endproducts or blends. Based on the selected end product or blend, a targetblend density or gravity may be set for a blending or mixing operationor process.

As the blending or mixing operation or process is initiated, thecontroller 606 may obtain or determine the density or gravity from eachof the tanks (e.g., tank A 618 and tank B 620) at the tank farm. Thecontroller 606 may further include, determine, or obtain an initial mixratio and/or flow rate for any flow control devices in the in-linemixing system 600 (e.g., flow control device 608). In an example, thedensity or gravity of each liquid to be blended may be a known value.Further and as noted above, the density or gravity of each liquid to beblended may be entered into the user interface and sent or transmittedto the controller 606. In another example, each tank (e.g., tank A 618and tank B 620) may include sensors or meters (for example, sensor 602and sensor 604). In other examples, sensors or meters (e.g., sensor 602and sensor 604) may be disposed on or added onto the pipe (e.g., thefirst output pipe 614 and second output pipe 616). For example, thesensors or meters may be clamp-on sensors or may be integrated into oronto the pipe or components of the pipe (such as a pump or flow controlvalve, as described above). In such examples, prior to or just after theinitiation of the blending or mixing operation or process, thecontroller 606 may determine or obtain the density or gravitymeasurements of the liquids to be blended from the sensors or meters (orobtain the density or gravity measurements where such measurements maybe stored, such as from another controller, sub-controller, or memory).The controller 606 may also obtain other data from the sensor or meters,such as flow rate, pressure, and/or other variables.

In yet other examples, one tank and pipeline associated with orcorresponding to the tank may not include a sensor or meter (in otherwords, tank A 618 may or may not include a sensor 602). If a density orgravity of a liquid to be blended is unknown and no sensor is availableto measure or determine the density or gravity, the controller 606 maydetermine the density or gravity based on the other determined orobtained densities or gravities, as well as the blend density or gravityobtained from sensor 610. For example, in FIG. 6A, a second density orgravity may be known or determinable (e.g., measurable via the sensor604 or a meter). As such, the controller 606 may determine the seconddensity or gravity. Further, the blended density or gravity may bedeterminable (as in, measureable via the sensor 610 or a meter). Yetfurther still, a ratio of the two liquids to be blended may be known (asin, the initial ratio of the liquids to be combined, such as a 50:50,60:40, 30:70 mix ratio and so on or a mix ratio from 1:99 to 99:1).Based on the ratio and the determined densities or gravities, theunknown density of a first liquid (e.g., the liquid stored in tank A618) may be determined, using, for example, the blended gravity as equalto the first ratio multiplied by the first density or gravity plus thesecond ratio multiplied by the second density or gravity (rearranged tosolve for the first density or gravity or the unknown value), as shownby the following equations:

Blended  Gravity = First  Gravity * First  Ratio + Second  Gravity * Second  Ratio${{First}\mspace{14mu} {Gravity}} = \frac{{{Blended}\mspace{14mu} {Gravity}} - {{Second}\mspace{14mu} {Gravity}*{Second}\mspace{14mu} {Ratio}}}{{First}\mspace{14mu} {Ratio}}$

If a first density or gravity is unknown, but the second density orgravity and blended density or gravity are known, the controller 606 maydetermine the first density or gravity. For example, if a synthetic fuelof a specific gravity of 0.857 is to be mixed with a heavier liquid atan initial mix ratio of 50:50, the controller 606 may determine theunknown specific gravity after measuring the blended gravity at thestart of the blending operation, which may be, for example, 0.886.Utilizing the equations above, the controller 606 may determine that thespecific gravity of the heavy liquid is 0.915 (e.g.,((0.886−50%)*0.857)/50%).

If all densities or gravities are known or once all densities orgravities have been determined, the flow of the liquids to be blendedmay be adjusted as needed or at specified time intervals, to produce anaccurate and precise blend. The specified time interval may be aninterval set by a user at the user interface. In another example, thespecified time interval may be an interval set in the controller 606. Insuch examples, the specified time interval may be a constant value or avariable value (variable, for example, depending on known or unknowndensities or gravities). A specified time interval may be an interval of10 to 20 minutes. In such examples, the amount of specified timeintervals may be based on the length of a specified time interval andthe total length of the blending or mixing operation or process (e.g., ablend operation of 4 hours may include 12 to 24 specified time intervalsof 10 to 20 minutes).

In another example, the specified time intervals may vary in length oftime as the blending or mixing operation or process proceeds. Forexample, neither density or gravity of any of the tanks (e.g., tank A618 and tank B 620) may be known, while in other examples, an estimatemay be known (e.g., based on which liquid is heavy and which is light).In such examples, none of the tanks (e.g., tank A 618 and tank B 620)may include sensors or meter to determine densities or gravities, exceptfor the sensor 610 to measure the blend density or gravity. Further, thecontroller 606 may check the blend density or gravity (via sensor 610),to allow for adjustment of the flow or mix ratio of liquids, morefrequently near the beginning of the blending or mixing operation orprocess (e.g., at the first 30 minutes of the blending operation) todetermine an accurate (e.g., if each density or gravity is unknown) ormore accurate (e.g., if an estimate of one or more of the densities orgravities is known) estimate of each liquids density or gravity. Theblend density or gravity may be checked or determined, for example,every 1 to 5 minutes or 1 to 10 minutes for the beginning (e.g., thefirst 30 minutes) of the blending or mixing operation or process and theflow rate or mix ratio adjusted. Such frequent measurements andadjustments may allow for the controller 606 to estimate the densitiesor gravities of each of the liquids to allow for further and lessfrequent adjustments during the blending or mixing operation or process,to ensure an accurate blend near (e.g., within about 1% of the targetblend density or gravity) or at the target blend density or gravity.After such estimates are determined, the controller 606 may check blenddensity or gravity and adjust the flow rate or mix ratios of liquidsless frequently (i.e., every 10 to 20 minutes), until the blendingoperation is finished.

At the end of each specified time interval, the controller 606 maydetermine the current density or gravity of the blend at the blend pipe612. The controller 606 may then compare the current density or gravityto the target blend density or gravity. If there is a difference betweenthe current density or gravity to the target blend density or gravity,the controller 606 may determine a corrected ratio of the first liquidand second liquid to reach the target blend density or gravity. Based onthe corrected ratio, the controller 606 may adjust the flow, via a flowcontrol device, of at least one of the liquids (e.g., the controller606, via the flow control device 608, may adjust the flow rate of thesecond liquid from tank B 620, while maintaining the proper pressure).

In an embodiment the flow control device 608 may include a pump, ameter, a pressure transducer, a flow control valve, and/or somecombination thereof. In another example, the sensor 604 may be a part ofthe flow control device 608. In another example, the sensor 604 may beincluded with or a part of the meter of the flow control device 608(e.g., a Coriolis meter, to measure flow and density). In such examples,each component of the flow control device 608 may be in signalcommunication with the controller 606. The flow control device 608 mayallow for mix ratio adjustments of the liquids being blended thereby toadjust the density or gravity. For example, the flow control device 608may, as noted, include a flow control valve. The flow control valve mayadjust the flow and/or pressure of the liquid based on opening orclosing/pinching the flow control valve. In another example, the flowcontrol device 608 may include a pump and variable speed drive. Thevariable speed drive may increase/decrease the speed of the pump toincrease/decrease the flow rate of a liquid to adjust the ratio ofliquids to be blended.

FIGS. 7A through 7B are schematic diagrams of a three-component in-linemixing system 700 positioned at a tank farm to admix three hydrocarbonliquids from separate tanks into a single pipeline according to anembodiment of the disclosure. As described above, a tank farm mayinclude two or more tanks (e.g., tank A 718, tank B 720, and tank 724).In such examples, the tank farm may include extensive piping, as well asnumerous other components, such as flow control devices 708, 728,various sensors 702, 704, 710, 722, and a controller 706. In suchexamples, a blending or mixing operation or process may include at leasttwo of the tanks or all three tanks. In such operations or processes,various initial ratios may be utilized (e.g., 50:45:5, 60:30:10, and soon). Further, a blend may be based on target blend density or gravity(the ratio determined based on the desired blend density or gravity). Insuch examples, once all the densities or gravities are gathered, thecontroller 706 may determine the actual blend density or gravity, viathe sensor 710 at the blend pipe 712. Based on the target blend densityor gravity compared to the actual blend density or gravity, as well asthe current liquid ratio and/or a target ratio, the controller 706 mayadjust the flow of one or more of the liquids in the blend while theblending or mixing operation or process occurs.

FIGS. 8A through 8B are schematic diagrams of a multi-component in-linemixing system 800 positioned at a tank farm to admix two or morehydrocarbon liquids from separate tanks into a single pipeline accordingto an embodiment of the disclosure. In such examples, the tank farm mayinclude any number of tanks (e.g., tank A 802, tank B 810, and tank C818 to tank N 826) to store various liquids for various blendingoperations. In such examples, different tanks may be used for differentblending operations. In other words, two or more tanks may be active ata time, while other tanks may be de-active (as in, not utilized in ablending operation). Such tanks may store particular liquids notutilized for specific blends or may be empty at that particular point intime. Thus, various amounts of liquids may be blended in such a tankfarm (from 3 component blending to 5 component blending or more).

As noted, the tank farm may include various components and some tanksmay utilize the same components (as in, tank B 810 when active may use aset of components, while tank C 818 remains de-active and tank C 818 mayuse the same set of components, while tank B 810 remains de-active). Thecomponents utilized at the tank farm may include flow control devices816, 824, 832, various sensors 804, 812, 820, 828, 836, and a controller838.

FIG. 9 is a simplified diagram illustrating a control system formanaging a multi-component in-line mixing system according to anembodiment of the disclosure. The control system, as described herein,may be a controller 901, one or more controllers, a PLC, a SCADA system,a computing device, and/or other components to manage a blendingoperation. The controller 901 may include one or more processors (e.g.,processor 902) to execute instructions stored in memory 904. In anexample, the memory 904 may be a machine-readable storage medium. Asused herein, a “machine-readable storage medium” may be any electronic,magnetic, optical, or other physical storage apparatus to contain orstore information such as executable instructions, data, and the like.For example, any machine-readable storage medium described herein may beany of random access memory (RAM), volatile memory, non-volatile memory,flash memory, a storage drive (e.g., hard drive), a solid state drive,any type of storage disc, and the like, or a combination thereof. Asnoted, the memory 904 may store or include instructions executable bythe processor 902. As used herein, a “processor” may include, forexample one processor or multiple processors included in a single deviceor distributed across multiple computing devices. The processor 902 maybe at least one of a central processing unit (CPU), asemiconductor-based microprocessor, a graphics processing unit (GPU), afield-programmable gate array (FPGA) to retrieve and executeinstructions, a real time processor (RTP), other electronic circuitrysuitable for the retrieval and execution instructions stored on amachine-readable storage medium, or a combination thereof.

The instructions may include an instruction 906 to obtain or determine afirst density or gravity. In such examples, at the beginning of or priorto start of a blending operation, the controller 901 may obtain thefirst density or gravity from a user (e.g., the density or gravityentered via a user interface). In another example, the controller 901may obtain the first density or gravity from a sensor. The controller901 may obtain the first density or gravity from a ticket or order slip(or another form including such data). In another example, thecontroller 901 may determine the density or gravity based on other knowndensities or gravities. The controller 901 may include the first densityor gravity as a preset value. In such examples, a particular tank may bestore the same liquid for each blending operation. As such, the densityor gravity of the liquid may be the same or slightly different perbatch. The instructions may include an instruction 908 to obtain asecond density or gravity, similar to that of or the same asinstructions 906. In other words, the second density or gravity may beobtained via a user at a user interface, via measurement (as in,measurement from a sensor), via determination based on othermeasurements and/or data, or via a preset density or gravity.

The instructions may include an instruction 910 to obtain a target blenddensity or gravity. Such a target blend density or gravity may bedetermined based on the product to be blended or mixed. In anotherexample, the target blend density or gravity may be based on user inputvia a user interface. In yet another example, the target blend densityor gravity may be preset or stored in the memory 904 of the controller901. The instructions may include an instruction 910 to, after aspecified time interval, obtain or determine the actual blend density orgravity. Such instructions 910 may determine the actual blend density orgravity based on a measurement from a blend sensor 920.

After reception of the actual blend density or gravity, the controller901 may compare the actual blend density or gravity to the target blenddensity or gravity. The instructions may include an instruction 914 to,based on a difference between the actual blend density or gravity andthe target blend density or gravity, determine a corrected ratio. Inother words, the corrected ratio may be the mix ratio of the first andsecond liquid (or any other liquids to be blended) transported to ablend pipe for mixing.

The instructions may include instructions 916 to, in response to adetermination of a corrected ratio, adjust the flow of one or more ofthe liquids, based on the corrected ratio. Such adjustments may occurduring operation or execution of the blending or mixing operation orprocess. For example and as noted, the target blend may be a 30 APIbend. If at a current ratio of 60:40, the blend is currently at 25 API,the lighter of the two fluids flow rate may be increased to increase theAPI gravity of the overall blend (e.g., an increase from 60:40 to 50:50,40:60, etc. to increase the API gravity).

For example, a blend may be a 60:40 (first liquid:second liquid) blendwith a target of an API of 30 degrees. In such examples, the firstliquid, which may be a heavier liquid, may be fed via gravity to theblending pipe at a constant flow and pressure and the second liquid,which may be a lighter liquid, may be fed to the blend pipe, via a flowcontrol device 922, at a set flow and/or pressure. At the beginning ofsuch a blending operation, the current or actual blend API may be 28degrees. Based on the difference between the target blend gravity andthe actual blend gravity and the new determined ratio, the flow controldevice 922 may increase the flow of the second liquid during theblending operation, thus adjusting the mix ratio or increasing the ratioof the second liquid in the blend to ensure that the API is increased,so as to reach the target API. Such operations may ensure an accurateblend that meets the target blend density or gravity.

Other instructions may include instructions to obtain a current flowrate and/or mix ratio based on data obtained from the flow controldevice 922 and/or the blend sensor 920. Further, at the initiation of ablending operation the controller 901 may set the initial flow rate ofliquids from each tank. The initial flow rate may be based on a knownfirst density and second density, on an estimate of the first densityand second density, or on an arbitrary mix ratio (e.g., an initial mixratio may be 50:50 and, as such, the flow rate, via the flow controldevice 922, may be set to an appropriate setting to allow for the firstliquid and second liquid to mix at the 50:50 ratio). In other examples,the flow rate of one liquid, e.g., the first liquid, may be a constantvalue, as the liquid may be gravity fed to the blend pipe. In suchexamples, the flow rate or mix ratio may be utilized to determineunknown densities or gravities.

FIG. 10 is another simplified diagram illustrating a control system formanaging a multi-component in-line mixing system according to anembodiment of the disclosure. In such examples, the controller 1001 mayinclude instructions to measure or obtain a density or gravity fromvarious sensors (e.g., blend sensor 1020, sensor 1012, sensor 1014,sensor 1016, sensor N 1018, etc.) or from a user interface 1030.Further, the controller 1001 may include instructions to determine acorrected ratio based on the determined or obtained densities orgravities. Further still, the controller 1001 may include instructionsto adjust the flow and/or pressure of one or more of the various liquidsbeing blended, via one or more flow control devices (e.g., flow controldevice 1022, flow control device 1024, flow control device 1026, flowcontrol device N 1028, etc.), based on the determined or obtaineddensities or gravities. Such adjustments may occur during continuousoperation of the blending or mixing operations or processes.

In an example, the sensors (e.g., blend sensor 1020, sensor 1012, sensor1014, sensor 1016, sensor N 1018, etc.) may provide measurements as adensity or as a gravity (e.g., a specific gravity). However, some valuesmay be entered via the user interface as an API gravity. For example, ifthere are no sensors associated with a first tank or first output pipe,a user may enter the density or gravity of the first liquid at the userinterface 1030. The user may enter such a value as an API gravity, whichmay typically be utilized to describe characteristics of hydrocarbonliquids. As such, the controller 1001 may include instructions toconvert measurements, whether from density or specific gravity, to anAPI gravity or to convert an API gravity to a density or specificgravity. In another example, the user interface 1030 may include anoption to select the type of measurement to enter when entering in adensity or gravity (e.g., a list or drop-down list includingmeasurements as density, specific gravity, or API gravity).

FIG. 11 is another simplified diagram illustrating a control system formanaging a multi-component in-line mixing system according to anembodiment of the disclosure. As noted above, the controller 1001 mayinclude instructions 1006 to measure or obtain the density or gravity ofliquid associated with a corresponding sensor or meter (e.g., blendsensor 1020). In some cases, a tank farm may include a sensor (e.g.,blend sensor 1020) corresponding to the blend pipe, rather than a sensorfor the blend pipe and for each tank or pipe corresponding to each tank.In such cases, the density or gravity from each tank may be known, inputat a user interface 1030, or be estimated as described above.

FIGS. 12 through 13 are flow diagrams, implemented in a controller, formanaging a multi-component in-line mixing system according to anembodiment of the disclosure. The method is detailed with reference tothe controller 1001 and system 1000 of FIG. 10. Unless otherwisespecified, the actions of methods 1200 and 1300 may be completed withinthe controller 1001. Specifically, methods 1200 and 1300 may be includedin one or more programs, protocols, or instructions loaded into thememory of the controller 1001 and executed on the processor or one ormore processors of the controller 1001. The order in which theoperations are described is not intended to be construed as alimitation, and any number of the described blocks may be combined inany order and/or in parallel to implement the methods.

At block 1202, the controller 1001 may obtain or determine a firstdensity or gravity from a first sensor 1012. In another example, thecontroller 1001 may obtain the first density or gravity from the userinterface 1030 (e.g., based on an input from a user). In anotherexample, the first density or gravity may be determined based on otherknown or determined densities or gravities. At block 1204, thecontroller 1001 may obtain or determine a second density or gravity froma second sensor 1014 (similar to that of obtaining or determining thefirst density or gravity from the first sensor 1012). In other examples,more densities or gravities, based on other liquids to be blended in ablending or mixing operation or process, may be obtained from othersensors located or disposed at the tank farm (e.g., a third sensor 1016,sensor N 1018, etc.).

At block 1206, a target blend density or gravity may be obtained. Insuch examples, the target blend density or gravity may be input at theuser interface 1030. The target blend density or gravity may be presetand stored in memory 1004. At block 1208, the controller 1001 maydetermine whether a specified time interval has passed. If the specifiedtime interval has not passed, the controller 1001 may continue to checkwhether the specified time interval has passed after a certain period oftime. If the specified time interval has passed, the controller 1001 mayobtain an actual blend density or gravity from a third sensor (e.g.,blend sensor 1020) located at the blend pipe. The actual blend densityor gravity may be the density or gravity of a blended liquid comprisedof a ratio of the first liquid, the second liquid, and/or other liquidsincluded in the blend operation.

At block 1212 the controller 1001 may compare the target density orgravity to the actual blend density or gravity. If the target blenddensity or gravity is equal to the actual blend density or gravity, thecontroller 1001 may wait for the next specified time interval to pass.If the values are not equal, at block 1214, the controller 1001 maydetermine a corrected ratio, based on the densities or gravities of eachliquid being blended, the target blend density or gravity, and theactual blend density or gravity. In another example, prior todetermination of a corrected ratio the controller 1001 may convert anynumber of measurements to different types of measurements, depending oncontroller 1001 configuration and/or measurements obtained from sensorsdisposed throughout the system. For example, the controller 1001 may beconfigured to determine a corrected ratio based on gravity, while thesensors may measure density. In such examples, the controller 1001 maybe configured to convert the densities measured to gravities, prior toeither comparison or determination of the corrected ratio. In anotherexample, the controller 1001 may be configured to determine a correctedratio based on density, while the sensors may measure gravity. In suchexamples, the controller 1001 may be configured to convert the gravitiesmeasured to densities, prior to either comparison or determination ofthe corrected ratio. In another example, the controller 1001 may bereconfigured to perform determinations or calculations based on themeasurements performed by the sensors. In other words, a controller 1001may be reconfigured to perform determinations based on density orgravity if the sensors measure density or gravity, respectively.

At block 1216, the controller 1001 may adjust the flow, via the flowcontrol device of either the first liquid and second liquid (e.g., viaflow control device 1022 and flow control device 1024, respectively),the second liquid (e.g., via the flow control device 1024), otherliquids being blended (e.g., flow control device 1026, flow controldevice 1028, etc.), or a combination thereof.

For example, a first liquid from a first tank may be gravity-fed to theblend pipe. In such examples, the flow control device for the secondliquid of the second tank may adjust the flow of the second liquid, thuscontrolling or adjusting the mix ratio of the first liquid and secondliquid. Similar to the equations noted above, the new ratio may becalculated based on the first liquid's density or gravity, the secondliquid's density or gravity, the actual blend density or gravity, andthe target blend density or gravity. The following equation may beutilized to determine the corrected ratio (while the equation is shownutilizing gravity, density or API gravity may be utilized):

${{Second}\mspace{14mu} {Ratio}} = \frac{{{Target}\mspace{14mu} {Blend}\mspace{14mu} {Gravity}} - {{First}\mspace{14mu} {Gravity}}}{{{First}\mspace{14mu} {Gravity}} - {{Second}\mspace{14mu} {Gravity}}}$

Based on the new second ratio, the flow control device may adjust theflow of the second liquid. In other examples, both the first liquid andsecond liquid may pass through a flow control device. In such examples,the first liquid flow and the second liquid flow may both be adjusted.While the equation described above is based on a two component blend,the equation may be utilized for a three or more component blend.

For FIG. 13, at block 1301, the controller 1001 may initiate a blendingprocess or receive a signal to initiate a blending process. In suchexamples, the controller 1001 may not begin the actual blending processuntil a first density or gravity and a second density or gravity aredetermined. In another example, the controller 1001 may start theblending process upon reception of the initiation signal or indicatorand determine the first and second densities or gravities as theblending process occurs.

At block 1302, the controller 1001 may determine whether a first densityor gravity of a first liquid from a first tank is known. If the firstdensity or gravity is unknown, at block 1304, the controller 1001 maydetermine the first density or gravity (e.g., via sensor, via theequations referenced above, or via a user interface 1030). At block1306, the controller 1001 may determine if a second density or gravityof a second liquid from a second tank is known. If the second density orgravity is unknown, at block 1308, the controller 1001 may determine thesecond density or gravity (e.g., via sensor, via the equationsreferenced above, or via a user interface 1030).

At block 1310, the controller 1001 may determine whether the targetblend density or gravity is known. If the target blend density orgravity is unknown, the controller 1001, at block 1312, may request thetarget blend density or gravity from a user (e.g., sending a prompt to auser interface indicating a target blend density or gravity may beentered to proceed). At 1314, if the target blend density or gravity hasnot been received the controller 1001 may wait for the target blenddensity or gravity. If the target blend density or gravity is received,the controller 1001, at block 1316, may determine the actual blenddensity or gravity, the blend density or gravity based on the density orgravity of the first and second liquid and the ratio the first andsecond liquid are blended or mixed at.

At block 1318, the controller 1001 may compare the blend density orgravity with the target blend density or gravity. If the blend densityor gravity and the target blend density or gravity do not match, atblock 1320 the controller 1001 may determine the corrected ratio, basedon the density or gravity of the first liquid, the second liquid, theblended liquid, and the ratio of the first liquid and second liquid. Atblock 1322, the controller 1001 may adjust any flow control devicespresent to adjust the flow of one or more of the liquids to be blendedor mixed.

At block 1324, the controller 1001 may determine whether the blendingprocess is finished. If the blending process is finished, the controller1001, at block 1326 may wait a specified time period and then determinethe blend density again. Once the blending process is finished, thecontroller 1001 may initiate another blending process.

FIGS. 14A, 14B, 14C, and 14D are schematic diagrams of in-line mixingsystems positioned at a tank farm 1400 to admix two or more hydrocarbonliquids from separate sets of tanks 1402, 1403 into a single pipelineaccording to an embodiment of the disclosure. In an embodiment, ratherthan employing components, such as pumps, meters, and sensors, at eachindividual tank at the tank farm 1400, a different configuration to,e.g., holistically, maintain pressure and flow rate of hydrocarbon fluidflows from a plurality of tanks to a single pipeline at a lower cost maybe utilized. Such configurations may include, for at least two sets ofin-series tanks 1402, 1403, pumps 1412, 1442 with correspondingspillback loops 1410, 1440 added to the at least two sets of in-seriestanks 1402, 1403. In one or more embodiments, each set of in-seriestanks 1402, 1403 may be physically separated, e.g., by distance, such as500 feet, 1,000 feet, 1,500 feet, 2,000 feet, 2,500 feet, 3,000 feet,3,500 feet, 4,000 feet, 4,500, feet, 5,000 feet, a full mile or more. Inother embodiments, each set of in-series tanks 1402, 1403 may be locatedat different tank farms, proximate tank farms, or at separate locationswithin the tank farm 1400.

In one or more such embodiments, each set of in-series tanks 1402, 1403may include a varying number of tanks (e.g., two tanks, three tanks, ormore). For example, a first set of tanks 1403 may include two sets oftanks in series, each set including three tanks. As noted, the first setof tanks 1403 may include several tanks, such as tank D 1422, tank E1424, tank F 1426, tank G 1434, tank H 1436, and tank I 1438. The firstspillback loop 1440 may loop around a portion of or all of the first setof tanks 1403 (for example, the first spillback loop 1440 as shown loopsaround pump 1442, tank G 1434, tank H 1436, and tank I 1438). In otherwords, the first spillback loop 1440 may include a first header 1445 towhich tank G 1434, tank H 1436, and tank I 1438 connect to via theirrespective output pipes (e.g., output pipe 1435), a pump 1442 that hasan inlet that connects to the first header 1445 and an outlet thatconnects to a first booster pipe 1457, and a first spillback pipe 1451.The first spillback pipe 1451 connects at one end portion to the firstbooster pipe 1457 at a point downstream of pump 1442 and connects at itsother end portion to the first header 1445 at a point upstream of thepoints where the output pipes (e.g., output pipe 1435) of tank G 1434,tank H 1436, and tank I 1438 connect to the first header 1445. In one ormore embodiments, the output pipes, the first header 1445, and the firstbooster pipe 1457 may be considered a single first pipe that delivershydrocarbon fluids/liquids from a set of tankage to junction 1452 (i.e.,the point of blending with other hydrocarbon fluids/liquids from anotherset of tankage). In one or more other embodiments, the first header 1445may extend downstream of pump 1442 such that pump 1442 is disposed inthe first header 1445 and the first spillback pipe 1451 connects to thefirst header 1445 both downstream of and upstream of pump 1442.

The first spillback loop 1440 may include a motor operated valve 1444, acontrol valve 1448, and a one-way valve 1461. The motor operated valve1444 may open and close (e.g., fully open and fully close) to allow forthe use of the first spillback loop 1440. In one embodiment, thecontroller 1460 may include instructions to open the motor operatedvalve 1444 upon initiation of a blending or mixing operation or process.In another example, the controller 1460 may include instructions to openor close the motor operated valve 1444 at any other point during theblending or mixing operation or process. The control valve 1448 may openand close at varying percentages to allow for adjustment of the flowrate and/or pressure of hydrocarbon liquids/fluids entering from thetanks (e.g., by adjusting the flow spilling back or flowing/enteringinto the spillback pipe 1451/loop). The one-way valve 1461 may preventhydrocarbon liquid/fluid from flowing in the reverse direction throughthe first spillback loop 1440 (i.e., by-passing pump 1442).

As noted above, each set of in-series tanks 1402, 1403 may include avarying number of tanks (e.g., two tanks, three tanks, or more). Forexample, a second set of tanks 1402 may include one set of tanks in“series.” As noted, the second set of tanks 1402 may include severaltanks, such as tank A 1404, tank B 1406, and tank C 1408. The secondspillback loop 1410 may loop around a portion of or all of the secondset of tanks 1402 (for example, the second spillback loop 1410 as shownloops around pump 1412, A 1404, tank B 1406, and tank C 1408). In otherwords, the second spillback loop 1410 may include a second header 1415to which tank A 1404, tank B 1406, and tank C 1408 connect to via theirrespective output pipes (e.g., output pipe 1405), a pump 1412 that hasan inlet that connects to the second header 1415 and an outlet thatconnects to a second booster pipe 1455, and a second spillback pipe1417. The second spillback pipe 1417 connects at one end portion to thesecond booster pipe 1455 at a point downstream of pump 1412 and connectsat its other end portion to the second header 1415 at a point upstreamof the points where the output pipes of tank A 1404, tank B 1406, tank C1408 connect to the second header 1415. In one or more embodiments, theoutput pipes, the second header 1415, and the second booster pipe 1455may be considered a single second pipe that delivers hydrocarbonfluids/liquids from a set of tankage to junction 1452 (i.e., the pointof blending with other hydrocarbon fluids/liquids from another set oftankage). In one or more other embodiments, the second header 1415 mayextend downstream of pump 1412 such that pump 1412 is disposed in thesecond header 1415 and the second spillback pipe 1417 connects to thesecond header 1415 both downstream of and upstream of pump 1412.

The second spillback loop 1410 may include a motor operated valve 1414,a control valve 1416, and a one-way valve 1462. The motor operated valve1414 may open and close (e.g., fully open and fully close) to allow forthe use of the second spillback loop 1410. In one embodiment, thecontroller 1460 may include instructions to open the motor operatedvalve 1462 upon initiation of a blending or mixing operation or process.In another example, the controller 1460 may include instructions to openor close the motor operated valve 1414 at any other point during theblending or mixing operation or process. The control valve 1416 may openand close at varying percentages to allow for adjustment of the flowrate and/or pressure of hydrocarbon liquids entering from the tanks(e.g., by adjusting the flow spilling back or flowing into the spillbackpipe/loop). The one-way valve 1462 may prevent backflow or hydrocarbonliquid/fluid from flowing in the reverse direction into and/or throughthe second spillback loop 1410 (i.e., by-passing pump 1412).

Each of the sets of in-series tanks (e.g., the first set of tanks 1403,the second set of tanks 1402, and/or another set of tanks at the tankfarm 1400), and each of the tanks therein, may include different typesof hydrocarbon liquids, with each of the hydrocarbon liquids having oneor more of a varying viscosity, density, amount, and/or exhibiting othercharacteristics. In one or more embodiments, the hydrocarbon liquid maybe a crude oil. A hydrocarbon liquid/fluid may flow from its respectivetank through the output pipe 1405, 1435 of the tank, into the header1415, 1445, and through a corresponding pump 1412, 1442 (e.g., disposedin the header). Thereafter, a portion of the hydrocarbon liquid/fluidmay then flow through a corresponding spillback loop 1410, 1440 (e.g.,based on percentage open of a control valve 1416, 1448). The remainingportion of the hydrocarbon liquid/fluid may flow to junction 1452.Junction 1452 is configured to allow for at least two hydrocarbonliquids to flow to a blend pipe 1453 (e.g., via second booster pipe 1455or first booster pipe 1457), where the at least two hydrocarbon liquidsmay be blended or mixed. As shown, the pipe connected to the junction1452 may either be the second booster pipe 1455 or an extension of thesecond header 1415. Similarly, the other pipe connected to the junction1452 may either be the first booster pipe 1457 or an extension of thefirst header 1445. Other pipes, to allow for other hydrocarbonliquid/fluids, may connect to junction 1452. Throughout a blendingoperation, the flow rate and pressure of hydrocarbon liquids/fluids fromthe tanks utilized for the blending operation may vary based ondifferent factors, such as liquid level in a tank, line speedups (e.g.,flow rate and pressure increase at the output line), and/or flowinterruptions, such as from switching or swapping from one tank toanother. In at least one embodiment, one of the spillback loops andassociated pumps (e.g., the first spillback loop 1440, the secondspillback loop 1410, or any other spillback loops for any other seriesof tanks at tank farm 1400, another tank farm or tank farms) may operateto allow for a continuous and/or constant flow rate and pressure tojunction 1452. The other spillback loops and pumps at the tank farm 1400may operate to adjust the flow rate of hydrocarbon liquid/fluid flow atjunction 1452, based on a target blend or mixture (either based on flowrate, density, or gravity).

In another embodiment, the tank farm 1400 may include one or more meters(e.g., meter 1420 and/or meter 1454) or sensors. The meters or sensorsmay measure flow rate, pressure, density, gravity, or some other valueor characteristic of hydrocarbon liquids flowing through an associatedportion of pipe or pipeline. The meters or sensors may be in fluidcommunication with the hydrocarbon liquid to measure the value orcharacteristic of the hydrocarbon liquid directly, or the meters orsensors may clamp on to the pipeline to measure the values orcharacteristics of the hydrocarbon liquids indirectly, e.g., viaultrasonic measurement.

During a blending or mixing operation, the pressure and flow rate ofhydrocarbon liquids/fluids that are recirculating in at least one of thespillback pipes/loops associated with a set of in-series tanks may beheld or maintained constant, e.g., at or driven to a set point, as aresult of control valve adjustments of the corresponding spillback loop.In another embodiment, the pressure and flow rate of hydrocarbonliquids/fluids flowing to junction 1452 from one of the booster pipes(e.g., the second booster pipe 1455 or the first booster pipe 1457) maybe held constant, e.g., at or driven to a set point, as a result ofcontrol valve adjustments of the corresponding spillback loop (in otherwords, the corresponding spillback loop may hold a constant flow from acorresponding booster pipe based on control valve adjustments), ratherthan holding the pressure and flow rate of hydrocarbon liquids/fluidsthat are recirculating in at least one of the spillback pipes/loopsconstant. Such adjustments, e.g., of the control valve, occur bychanging the opened/closed percentage of the control valve of thecorresponding spillback loop (e.g., control valve 1416 of the secondspillback loop 1410 and/or control valve 1448 of the first spillbackloop 1440), based on an estimated or calculated spillback flow rate. Theestimated or calculated spillback flow rate may be determined from ameasured differential pressure across the control valve of the spillbackloop, the density of the hydrocarbon fluid/liquid flowing through thespillback pipe/loop, and the open percentage of the control valve. Inone or more embodiments, the differential pressure may be measured via adifferential pressure transmitter (DPIT) (e.g., DPIT 1418 of the secondspillback loop 1410 and/or the DPIT 1450 of the first spillback loop1440), as will be understood by those skilled in the art. Based on themeasured differential pressure, hydrocarbon density and characteristicsof the control valve (e.g., open percentage, pump curves, etc.), theestimated or calculated spillback flow rate may be used to adjust theopen percentage of the control value, e.g., by comparing the estimatedor calculated spillback flow rate to a desired or pre-selected flow rateset point.

A blending/mixing operation or process, according to one or moreembodiments, may begin by establishing a target blend ratio (e.g.,50:50, 60:40, etc.) of the hydrocarbon fluid/liquid from the first setof in-series tank to be blended with the hydrocarbon fluid/liquid fromthe second set of in-series tanks. A flow rate for hydrocarbonfluid/liquid recirculation within at least one of the spillback loopsassociated with one set of in-series tanks is set at a set point, i.e.,to be maintained at a constant or near constant flow rate. After thepumps 1412, 1442 begin pumping a portion of their hydrocarbonliquids/fluids through their respective spillback pipes/loops and theremaining portion of their hydrocarbon liquids/fluids to junction 1452,a controller 1460 may estimate or measure flow rate of the hydrocarbonliquid in the first spillback loop 1440 and/or second spillback loop1410 associated with the first set of in-series tanks 1403 and secondset of in-series tanks 1402, respectively. The flow rate in a spillbackpipe/loop may be estimated in proportion to the square root of thepressure differential at the control valve 1448, 1416 over the densityor specific gravity (known based on previous analysis of the hydrocarbonliquid or via user input) multiplied by the percentage that the controlvalve 1448, 1416 is open, as represented by the equation below:

${{Flow}\mspace{14mu} {Rate}} \propto {{Valve}\mspace{14mu} {Open}\mspace{14mu} {Percentage}*\left. \sqrt{}\left( \frac{\Delta \; {Pressure}}{Gravity} \right) \right.}$

As will be understood by those skilled in the art, the valve openpercentage is a proxy for the cross-sectional area through which theflow passes (i.e., similar to the cross-sectional area of an orifice inan orifice plate), which is a characteristic specific to the controlvalve 1448, 1416. Based on this estimated/calculated flow rate, thecontroller 1460 may adjust the control valve 1448 and/or control valve1416 (open to increase flow rate; close to decrease flow rate) to ensurethat the calculated flow rate through the first spillback loop 1440and/or second spillback loop 1410 matches the established set point. Inthis way, the measured differential pressure along with the openpercentage of the control valve are used to maintain a constant flowrate of the hydrocarbon liquids in the first spillback loop 1440 or inthe second spillback loop 1410.

In conjunction with or at the same time as the above-described process,a blend flow meter (e.g., meter 1454) may measure the flow rate of thecombined hydrocarbon liquids in blend pipe 1453 downstream of junction1452 and meter 1420, e.g., connected to second booster pipe 1455 (oranother meter disposed at the tank farm 1400) may measure the flow rateof hydrocarbon liquid or liquids from the second series of in-line tanks1402, which are upstream of junction 1452. While not shown on FIG. 14A,those skilled in the art will recognize that meter 1420 couldalternatively be connected to first booster pipe 1457 to measure flowrate of the hydrocarbon fluid/liquid passing from tanks 1403 to junction1452. As may be understood from FIG. 14A, the difference in flow ratebetween that measured by the blend flow meter and that measured by meter1420 is the flow rate originating from the first set of in-series tanks1403. Based on those measurements and subsequent calculations, thecontroller 1460 may determine ratios of flow originating from the firstset of in-series tanks 1403 (i.e., calculated) and the flow originatingfrom the second set of in-series tanks 1402 (i.e., measured by meter1420) and compare such ratios against the desired blend ratio. If thecalculated blend ratio strays too far (e.g., outside of a set bound,such as greater than 10%, greater than 5%, greater than 2% or evengreater than 1%) from the desired blend ratio, then the controller 1460may adjust the flow in the first spillback loop 1440 (involving thefirst set of in-series tanks 1403) or second spillback loop 1410(involving the second set of in-series tanks 1402) by opening or closingthe control valve 1448 or the control valve 1410, respectively. Such anadjustment may alter the pressure and/or flow of the hydrocarbon liquidflowing through the second spillback loop 1410 or first spillback loop1440, such that a greater flow or lesser flow of the hydrocarbon liquidis passed to junction 1452 to blend with the hydrocarbon liquidoriginating from the first set of in-series tanks 1403 or second set ofin-series tanks 1402, as the case may be.

It should be noted that, in one or more embodiments, one or more of thepumps disposed in the tank farm may be a set speed/frequency pump or avariable speed/variable frequency drive (VFD) pump. If the pump is a VFDpump, then the pump may speed up or slow down to increase or decrease,respectively, pressure and/or flow rate, while the control valve in thespillback loop may adjust open percentage in conjunction with theadjusted speed/frequency of the pump to further alter the flow and/orpressure. In another embodiment, the VFD pump may provide for a slow orsoft start up to the blending operation. The slow or soft start up mayprovide for a gradual ramp up of power to the VFD pump, rather thanimmediately powering up to full power. Any of the pumps disposedthroughout the tank farm 1400 may be VFD pumps. For example, and not tobe limiting in any way, pump 1430 may connect to VFD 1431, such that thevariable speed or frequency allows for thorough mixing of hydrocarbonliquids from tank D 1422, tank E 1424, and tank F 1426.

As illustrated in FIGS. 14A and 14B, the tank farm 1400 includes sets ofin-line series tanks (e.g., the first set of in-line series tanks 1403and the second set of in-line series tanks 1402). In another embodiment,and as illustrated in FIG. 14C, the tank farm 1400 may include anynumber of tanks, based on the physical size of the tank farm and/orcost. In other words, more than just three or six tanks may be includedin each set of in-series tanks. For example, the first set of in-seriestanks, may include tank B1 1480, tank B2 1481, tank B3 1482, and/or upto tank BN 1483. The first set of in-series tanks may also include tankC1 1484, tank C2 1485, tank C3 1486, and/or up to tank CN 1487. Thesecond set of in-series tanks may include tank A1 1488, tank A2 1489,tank A3 1490, and/or up to tank AL 1491. In another example, other setsof tanks (e.g., in-series, in parallel, and/or individual tanks) withcorresponding pumps and spillback loops may be disposed throughout thetank farm 1400 to allow for mixing of two or more hydrocarbonliquid/fluid streams from two or more sets of tanks (e.g., to createtwo-component, three-component, or other multi-component blends).

As illustrated in FIG. 14D, the tank farm 1400 may include a pluralityof spillback loops to control various flow rates and/or pressure fromvarious hydrocarbon liquid sources. In such embodiments, the tank farm1400 may include spillback loop A 1490A, spillback loop B 1490B,spillback loop C 1490C, and/or up to spillback loop N 1490N. Asillustrated in FIGS. 14A through 14C, each spillback loop may looparound (i.e., be connected to) a number of tanks. In FIG. 14D, eachspillback loop may loop around tanks and/or some other hydrocarbonliquid source. For example, a hydrocarbon liquid may flow into thespillback loop 1490A (or any of loops 1490A to 1490N) from a hydrocarbonliquid source that is not a tank or nearby tankage, e.g., a pipeline.

FIG. 15 is a schematic diagram of an in-line mixing system positioned ata tank farm 1500 to admix two or more hydrocarbon liquids from separatesets of tanks, e.g., sets of in-series crude tanks, into a singlepipeline, according to an embodiment of the disclosure. In oneembodiment, sensors 1502, 1504, 1506, 1508, 1510, 1512, 1514, 1516, and1518 may be associated with and/or connected to pipes throughout thetank farm 1500 to measure various characteristics of hydrocarbonliquids. As illustrated in FIGS. 14A, 14B, 14C, and 14D, the tank farm1400 may utilize a DPIT (e.g., DPIT 1418 and DPIT 1450) to measurepressure differential across a control valve positioned in a spillbackpipe, and using such measurement, estimate/calculate the flow rate ofhydrocarbon fluid/liquid flowing through the control valve 1416, 1448.In another embodiment, sensors 1504, 1506 may measure the pressure attheir respective locations and may provide a pressure differential(e.g., as shown across control valve 1416) to a controller. In this way,sensor 1504, 1506 may be used to measure pressure differential, ratherthan or in addition to a DPIT, for flow rate estimation/calculation.Additionally, sensors 1502, 1512 may be utilized to directly measure aflow rate, pressure, density, or gravity. Sensors 1518 may measure or beutilized to determine density, gravity, viscosity, or othercharacteristics of a hydrocarbon liquid/fluid in a corresponding tank.In one or more embodiments, the sensors may each provide multipledifferent types of data, such as two or more of flow rate, pressure,density, or gravity. In addition, varying numbers of additional sensorsmay be associated with and/or connected to pipes and/or tankagethroughout the tank farm 1500. For example, one configuration mayinclude sensor 1504 or sensor 1506, but not both. Data gathered from thevarious sensors may be utilized to adjust control valves 1416, 1448 intheir respective spillback pipes and thus the flow rate and pressure ofhydrocarbon liquids that flow or recirculate through the respectivespillback pipes. In one or more embodiments, at least one of the controlvalves 1416, 1448 is adjusted on a continuous or semi-continuous basisusing such data in order to drive the flow rate or pressure of flowthrough the control valve towards a set point, i.e., a constant. Aspreviously described, adjustment of the control valves 1416, 1448regulates the flow or recirculation of hydrocarbon fluids/liquids (i.e.,that originated from the respective set of tanks) via the firstspillback loop 1440 and/or the second spillback loop 1410. This in turnregulates the portion of hydrocarbon fluid/liquid flow that is pumped bypump 1412, 1442 that enters into the respective spillback pipe (and thusthe spillback loop 1410, 1440) versus the portion of hydrocarbonfluid/liquid flow that is pumped by pump 1412, 1442 that continuesflowing to junction 1452 or the blend point.

FIG. 16 is a simplified diagram illustrating a control system formanaging a multi-component in-line mixing system according to anembodiment of the disclosure. Similar to the controller described abovein relation to FIGS. 9, 10, and 11, controller 1601 may include aprocessor 1602 or one or more processors. The controller 1601 mayinclude memory 1604 to store instructions. The instructions may beexecutable by the processor 1602. The instructions may includeinstructions 1606 to determine or measure a first flow rate. The firstflow rate may be a flow rate of a first hydrocarbon liquid from a firstset of tanks at a tank farm. The first flow rate may be measured by afirst meter 1618, sensor, or a first flow meter. The first meter 1614may be a clamp on device (i.e., an ultrasonic flow meter) or may beintegrated into or with the associated piping.

The instructions may include instructions 1608 to determine or measure ablend flow rate of the blend flow. The blend flow may be the sum of thefirst flow and a second flow. The second flow rate may be a flow rate ofa second hydrocarbon liquid from a second set of tanks at the tank farm.In such examples, the second flow rate may be unknown or estimated. Theblend flow rate may be measured by a blend meter 1620, sensor, or blendflow meter. The blend meter 1620 may be a clamp on device (i.e., anultrasonic flow meter) or integrated into or with the associated piping.

The instructions may include instructions 1610 to determine or estimatethe second flow rate of a second hydrocarbon liquid. The second flowrate may be determined based on the first flow rate and the blend flowrate. For example, if the blend flow rate is equal to 10,000 barrels perhour and the first flow rate is 6,000 barrels per hour, then the secondflow rate may be determined to be 4,000 barrels per hour. In anotherexample, the second flow rate may be measured by another meter disposedat the tank farm (not shown).

The instructions may include instructions 1612 to determine a firstspillback flow rate. In an example, the actual flow rate of the firsthydrocarbon liquid may be known. However, the amount of hydrocarbonliquid flowing through an associated spillback pipe may be unknown. Todetermine the amount of hydrocarbon liquid flowing through the spillbackloop (i.e., the spillback pipe), controller 1601 may measure data fromsensor 1 1622 and spillback control valve 1 1624. In such examples, thesensor 1 1622 may be a DPIT or a different sensor to measure relevantpressure/flow rate data. The controller 1601 may determine the firstspillback loop flow rate as a function of the differential pressureacross spillback control valve 1 1624, the density of the hydrocarbonliquid flow through the spillback loop (i.e., across the spillbackcontrol valve 1 1624), and the percentage that the spillback controlvalve 1 1624 is open (among other control valve characteristics asunderstood by those skilled in the art), as previously described. Thecontroller 1601 may compare the determined first spillback loop flowrate to a desired set point (e.g., user entered value or controllerentered value) and then determine whether the flow of hydrocarbon liquidshould be increased or decreased across the spillback control valve 11624. If such flow is to be increased slightly, then the controller 1601may determine how much to open the spillback control valve 1 1624 andtransmit a signal to the spillback control valve 1 1624 to open to thatspecified percentage, e.g., the spillback control valve 1 1624 may beopened by a proportional amount. If such flow is to be decreasedslightly, then the controller 1601 may determine how much to close thespillback control valve 1 1624 and transmit a signal to the spillbackcontrol valve 1 1624 to close to that specified percentage, e.g., thespillback control valve 1 1624 may be closed by a proportional amount.The controller 1601 then, after an optional period of time for the flowthrough the spillback pipe to attain steady state, again determines thefirst spillback loop flow rate, compares the determined value to the setpoint and adjusts the spillback control valve 1 1624 to drive the firstspillback loop flow rate toward the set point. In one or moreembodiments, the controller 1601 continues to measure the actual flowrate of the first hydrocarbon liquid via first meter 1618, which is theflow of the first hydrocarbon liquid (i.e., in FIG. 14A-B, the firsthydrocarbon is the hydrocarbon liquid from either tanks 1402 or tanks1403 depending on whether the flow meter is disposed in or on the secondbooster pipe 1455 or the first booster pipe 1457) that flows on towardthe blend point (and is not recirculated through the spillback pipe).The controller 1601 may establish the set point for the first spillbackflow rate to maintain a spillback flow rate that provides adequate flowof the first hydrocarbon liquid to junction 1452 (FIG. 14A-C) or theblend point, or to maintain a minimum flow through the pump of thespillback loop such that the pump operates in range that extends pumplife.

The instructions may include instructions 1614 to determine a secondspillback flow. In an example, an estimate flow rate of the secondhydrocarbon liquid may be known (e.g. as the difference between themeasured flow rate of the blend flow via blend meter 1620 and themeasured flow rate of the first hydrocarbon liquid via first meter1618). However, the amount of hydrocarbon liquid flowing through anassociated spillback may be unknown. To determine the amount ofhydrocarbon liquid flowing through the spillback loop (i.e., thespillback pipe), controller 1601 may measure data from sensor 2 1626 andspillback control valve 2 1628. In such examples, the sensor 2 1626 maybe a DPIT or a different sensor to measure relevant pressure/flow ratedata. The controller 1601 may determine the second spillback loop flowrate as a function of the differential pressure across spillback controlvalve 2 1628, the density of the hydrocarbon liquid flow through thespillback loop (i.e., across the spillback control valve 2 1628), andthe percentage that the spillback control valve 2 1628 is open (amongother control valve characteristics as understood by those skilled inthe art), as previously described. The controller 1601 may compare thedetermined second spillback loop flow rate to a desired set point (e.g.,user entered value or controller entered value) and then determinewhether the flow of hydrocarbon liquid should be increased or decreasedacross the spillback control valve 2 1628. If such flow is to beincreased slightly, then controller 1601 may determine how much to closethe spillback control valve 2 1628 and transmit a signal to thespillback control valve 2 1628 to close to that specified percentage,e.g., the spillback control valve 2 1628 may be closed by a proportionalamount. If such flow is to be decreased slightly, then the controller1601 may determine how much to close the spillback control valve 2 1628and transmit a signal to the spillback control valve 2 1628 to close tothat specified percentage, e.g., the spillback control valve 2 1628 maybe closed by a proportional amount. The controller 1601 then, after anoptional period of time for the flow through the spillback pipe toattain steady state, again determines the second spillback loop flowrate, compares the determined value to the set point and adjusts thespillback control valve 2 1628 to drive the second spillback loopflowrate toward the set point.

In one or more embodiments, the controller 1601 may establish the setpoint for the second spillback flow rate to maintain a spillback flowrate that provides adequate flow of the second hydrocarbon liquid tojunction 1452 (FIG. 14A-c) or the blend point, or to maintain a minimumflow through the pump of the spillback loop such that the pump operatesin range that extends pump life. In one or more embodiments, thecontroller 1601 may establish the set point by comparing the first flowrate, the blend flow rate and/or the second flow rate to assess whetherthe desired ratio of the first hydrocarbon flow to the secondhydrocarbon flow is achieved in the blend flow. As will be understood bythose skilled in the art, such comparisons may be made by comparingratios of first hydrocarbon flow rate to blend flow rate, firsthydrocarbon flow rate to second hydrocarbon flow rate, secondhydrocarbon flow rate to blend flow rate and the like to corresponding,desired ratios in the blend flow. Additionally, pressure or other flowcharacteristics of the first hydrocarbon liquid flow preceding junction1452 or the blend point, pressure or other flow characteristics of thesecond hydrocarbon liquid flow preceding junction 1452 or the blendpoint, and/or the pressure or other flow characteristics of the blendflow may also be used to determine if the desired ratio of firsthydrocarbon liquid to second hydrocarbon liquid is present in the blendflow. Based on such comparisons, the controller 1601 may determine thatthe flow rate of the second hydrocarbon liquid/fluid at junction 1452 orthe blend point should be increased or decreased relative the flow rateof the first hydrocarbon liquid/fluid at junction 1452 or the blendpoint. The controller 1601 may then determine the magnitude of such flowrate increase or decrease and set the set point of the second spillbackflow rate according. Thereafter, the controller 1601 generates and sendsone or more signals to the spillback control valve 2 1628 to adjust itsopen percentage accordingly to drive the spillback loop flow rate towardthe new set point (i.e., based on the desired ratio of first to secondhydrocarbon in the fluid blend), thereby modifying the spillback loopflow rate and subsequently the flow rate of the second hydrocarbonliquid/fluid flowing to junction 1452 or the blend point. While FIG. 16has been described herein with the flow meter measuring the first flowrate (i.e., of the first hydrocarbon liquid flow), the flow rate of thesecond hydrocarbon liquid flow (i.e., at/preceding junction 1452) beingdetermined as the difference between the measured blend flow rate andthe first flow rate, and the first spillback loop flow rate beingmaintained constant or nearly constant (e.g. being driven toward a setpoint) while the corresponding set point of the second spillback loopflow rate is adjusted to drive the ratio of the first to secondhydrocarbon liquid in the blend flow toward a desired ratio, thoseskilled in the art will appreciate that the opposite configurations (andother configurations) may be equally employed. Thus, in one or moreembodiments, a first flow meter 1618 measures the flow rate of thesecond hydrocarbon fluid, the flow rate of the first hydrocarbon fluidis determined as the difference between the blend flow rate and the flowrate of the second hydrocarbon fluid, and the second spillback loop flowrate is maintained constant or nearly constant while the correspondingset point of the first spillback loop flow rate is adjusted to drive theratio of the first to second hydrocarbon liquid in the blend flow towarda desired ratio.

As noted above, the controller 1601 may include instructions 1616 toadjust flow rate and pressure of one or more of spillback control valve1 1624, spillback control valve 2 1628, or other spillback controlvalves. The controller 1601 may generate and send signals to therespective control valve to adjust open percentage of the control valve,thereby modifying the flow rate and/or pressure of hydrocarbon flowacross the control valve in the spillback loop. For example, if twohydrocarbon liquids from two different tank areas of the tank farm areutilized, then at least one of the spillback control valves at thespillback loop (e.g., spillback control valve 1 1624 and/or spillbackcontrol valve 2 1628) associated with those respective tank areas may beadjusted based on a target blend ratio (i.e., the desired or targetedratio of the first hydrocarbon liquid to the second hydrocarbon liquidin the blend flow), an actual blend ratio, and/or an established setpoint spillback flow rate. The actual blend ratio may be based on thefirst flow rate, the estimate of the second flow rate, the blend flowrate, and/or other hydrocarbon liquid data (e.g., density, gravity,etc.). In one or more embodiments, controller 1601 may generate and sendsignals to each spillback control valve (e.g., spillback control valve 11624 and spillback control valve 2 1628) to directly adjust its openpercentage based on a difference between the target blend ratio and theactual blend ratio and/or based on an established set point spillbackflow rate.

In another example, the controller 1601 may connect to a user interface1630. A user may input various data points at the user interface 1630,such as a target blend ratio, a density or gravity of any of thehydrocarbon liquids to be mixed/blended, an amount of respectivehydrocarbon liquids to be mixed and/or the type of hydrocarbon liquidsto be mixed.

FIG. 17 is a flow diagram, implemented in a controller, for managing amulti-component in-line mixing system according to an embodiment of thedisclosure. The method 1700 is detailed with reference to the controller1460 and system 1400 of FIG. 14B. Unless otherwise specified, theactions of method 1700 may be completed within the controller 1460.Specifically, method 1700 may be included in one or more programs,protocols, or instructions loaded into the memory of the controller 1460and executed on the processor or one or more processors of thecontroller 1460. The order in which the operations are described is notintended to be construed as a limitation, and any number of thedescribed blocks and/or additional steps may be combined in any orderand/or in parallel to implement the methods

At block 1702, controller 1460 may initiate a blending or mixingoperation or process. In an example, a user may initiate the blending ormixing operation or process at the controller 1460 or at a computingdevice in signal communication with the controller 1460. In anotherexample, upon initiation, prior to initiation, or after initiation, auser may enter in data or details regarding the blending operation orprocess, such as a target blend ratio, a density or gravity of any ofthe hydrocarbon liquids to be mixed/blended, and/or an amount ofrespective hydrocarbon liquids to be mixed and/or the type ofhydrocarbon liquids to be mixed.

At block 1704, the controller 1460 may receive a target blend ratio. Thecontroller 1460 may receive the target blend ratio via a user interface,as described above. The controller 1460 may also be preset with a targetblend ratio or may be preset with different selectable target blendratios. At block 1706, the controller 1460 may determine a target firstflow. The target first flow may be the flow rate at which the first flowis set to. In another example, the controller may include a targetsecond flow. At block 1708, the controller 1460 may determine a targetblend flow. In an example, the target blend flow may be entered in via auser interface. In another example, the target blend flow may be storedin the controller 1460 or may include a selectable list of target blendflows.

At block 1710, the controller 1460 may receive or determine a density orgravity of the first hydrocarbon liquid. In such examples, a user mayenter the density or gravity at a user interface connected to thecontroller 1460. In another example, sensors may be connected to and/orotherwise associated with pipes and/or tankage throughout the tank farm1400. In such examples, the sensors may measure the density of eachhydrocarbon liquid. Similarly, at block 1712, the controller 1460 mayreceive or determine a density or gravity associated with the secondhydrocarbon liquid.

At block 1714, as the actual blending operation or process begins, ameter (e.g., meter 1420) or sensor may measure a first flow rate of afirst hydrocarbon liquid to be blended or mixed. At block 1716, ashydrocarbon liquids are mixed at junction 1452 (or another blend point)and begin to pass through the blend flow pipe (e.g., the mixingpipeline), another meter 1454 may measure the blend flow rate.

At block 1718, the controller 1460 may measure the pressure differentialat the control valve 1448 of the spillback loop via a DPIT (e.g., DPIT1450) or other sensor. At block 1720, the controller 1460 may measure orestimate a first flow of a first hydrocarbon liquid through the firstspillback loop 1440 based on the differential pressure over the controlvalve 1448 at the first spillback loop 1440, the density or gravity ofthe liquid flowing through the spillback loop, and the open percentageof the control valve 1448.

At block 1722, the controller 1460 may determine a second flow ratebased on the measured first flow rate and the measured blend flow rate.At block 1724, the controller 1460 may measure the pressure differentialat the control valve 1416 of the spillback loop via a DPIT (e.g., DPIT1418) or other sensor. At block 1726, the controller 1460 may measure orestimate a second flow of a second hydrocarbon liquid through the secondspillback loop 1410 based on the differential pressure over the controlvalve 1418 at the second spillback loop 1410, the density or gravity ofthe liquid flowing through the spillback loop, and the open percentageof the control valve 1410.

At block 1728, based on the measured first flow rate, the target firstflow rate, and the estimated first spillback flow, the controller 1460may determine whether to adjust the flow rate of the first hydrocarbonliquid. For example, the controller 1460 may determine to adjust thecontrol valve 1448 based on an established set point for a spillbackflow rate (e.g., the flow rate through the first spillback loop 1440) inorder to drive the estimated first spillback flow toward the establishedset point. As described above, the first flow rate and the spillbackflow rate may be adjusted via control valve 1448 in the spillback loop(e.g., first spillback loop 1440). At block 1730, if the first flow rateis to be adjusted, e.g., to maintain the flow through the firstspillback pipe/loop at a constant flow or driven toward a constant flow,the control valve 1448 at the spillback loop (e.g., first spillback loop1440) may open or close to some degree, depending on whether the flowrate is to increase or decrease (i.e., opening the control valve 1448increases spillback flow and decreases first flow rate while closing thecontrol valve 1448 decreases spillback flow and increases first flowrate). Such open percentage may be based on the estimated firstspillback flow rate and/or based on the established set point for thefirst spillback flow rate.

At block 1732, the controller 1460 may determine whether the second flowrate is to be adjusted. The determination may be based on the first flowrate, the second flow rate, the blend flow rate, an actual blend ratio,the target blend ratio, and/or an established set point for theestimated second spillback flow rate. At block 1734, if it is determinedthat the second flow rate is to be adjusted, e.g., to drive the actualblend toward the target blend ratio, then the control valve 1416 at thespillback loop (e.g., second spillback loop 1410) may open or close tosome degree, depending on whether the flow rate is to increase ordecrease (i.e., opening the control valve 1416 increases spillback flowand decreases second flow rate while closing control valve 1416decreases spillback flow and increases second flow rate). In an example,the controller 1460 may determine whether the first flow or the secondflow should be adjusted based on the target blend ratio and an actualblend ratio. The actual blend ratio may be determined via the first flowrate, the estimated second flow rate, and/or the blend flow rate orother flow characteristics thereof (e.g., pressure). In another example,and as described above with respect to blocks 1728 and 1730, one of theflow rates (e.g., the first flow rate, the second flow rate, the firstspillback flow rate, and/or the second spillback flow rate) may be keptat a constant or near constant value throughout the blending process viaspillback control valve adjustments, thus only the other flow rates maybe adjusted to control blend ratios.

At block 1736, the controller 1460 may determine whether the blendingoperation or process is finished or complete. If not, at block 1738, thecontroller 1460 may wait for a specified time interval or period of timebefore further adjusting flow rates and/or pressures, e.g., to permitthe hydrocarbon liquid flows to achieve steady state or near steadystate. If the blending operation or process is finished, the controller1460 may wait for a new blending operation/process to be initiated ormay begin an already queued blending operation/process.

Experimental Data

Experiments were conducted to test two-component and three-componentin-line mixing systems as described herein. Testing was conducted at apipeline origination station having a tank farm housing variousdifferent types of crude oil and other hydrocarbon liquids. In a firstblending operation run, two different types of crude were blended usinga two-component in-line mixing system (e.g., having a gravity-fed streamcontaining a first fluid and a controlled feed stream containing asecond fluid) with a target mix ratio of 50:50 (second fluid:firstfluid). The two-component blending operation run was conducted for threehours with constant measurement of the actual percentage of thecontrolled feed stream being delivered in the total blended fluid flow(e.g., based on the measured flow rate of the crude oil in thecontrolled feed stream).

Table 1 includes data from the two-component blending operation runperformed at the pipeline origination station. As shown in Table 1, theaverage actual percentage of the controlled feed stream was 49.87% overthe duration of the three-hour two-component blending operation runbased on a target set point ratio of 50:50 in the blended fluid flow. Asindicated in Table 1, this represents a 0.13% linear difference and a0.26% percent difference between the actual mix ratio and the target setpoint mix ratio. It should be noted that the percentage differencebetween the actual mix ratio and the target mix ratio would be expectedto be even lower if the blending operation testing run were to beconducted for a longer duration (e.g., for 6 hours, or 9 hours, or 12hours, or more).

TABLE 1 Average Actual Target Linear Percent Percentage PercentageDifference Difference (%) (%) (%) (%) 49.8684% 50% 0.132% −0.2632%

In a separate blending operation run, three different types of crude oilwere blended using a three-component in-line mixing system (e.g., havinga gravity-fed stream containing a first fluid and two controlled feedstreams containing a second fluid and a third fluid, respectively) witha target mix ratio of 50:46:4 (third fluid:second fluid:first fluid).The three-component blending operation run was conducted for six hourswith constant measurement of the actual percentage of both controlledfeed streams being delivered in the total blended fluid flow (e.g.,based on the measured flow rate of the crude oil in each of thecontrolled feed streams).

Table 2 includes data from a blending operation run performed at apipeline origination station using a three-component in-line mixingsystem according to the disclosure. As shown in Table 2, the averageactual percentage of the third fluid was 49.95% over the duration of thesix-hour three-component blending operation run based on a target setpoint ratio of 50:46:4 (third fluid:second fluid:first fluid) in theblended fluid flow. As indicated in Table 2, this represents a 0.05%linear difference and a 0.09% percent difference between the actualpercentage of the third fluid and the target set point percentage of thethird fluid. As also shown in Table 2, the average actual percentage ofthe second fluid was 49.89% over the duration of the six-hourthree-component blending operation run based on a target set point ratioof 50:46:4 (third fluid:second fluid:first fluid) in the blended fluidflow. As indicated in Table 2, this represents a 0.11% linear differenceand a 0.25% percent difference between the actual percentage of thesecond fluid and the target set point percentage of the second fluid. Itshould be noted that the percentage difference between the actual mixpercentages and the target mix percentages would be expected to be evenlower if the blending operation testing run were to be conducted for alonger duration (e.g., for 9 hours, 12 hours, 15 hours, or more).

TABLE 2 Average Actual Target Percentage- Percentage- Linear PercentThird Third Difference Difference Fluid (%) Fluid (%) (%) (%) 49.9547%50% 0.045% −0.0906% Average Actual Target Percentage- Percentage- LinearPercent Second Second Difference Difference Fluid (%) Fluid (%) (%) (%)45.8859% 46% 0.114% −0.2481%

The present application, as noted, is a Continuation-in-Part of U.S.application Ser. No. 17/247,700, filed Dec. 21, 2020, titled “METHODSAND SYSTEMS FOR INLINE MIXING OF HYDROCARBON LIQUIDS BASED ON DENSITY ORGRAVITY”, which claims priority to and the benefit of U.S. ProvisionalApplication No. 63/198,356, filed Oct. 13, 2020, titled “METHODS ANDSYSTEMS FOR INLINE MIXING OF PETROLEUM LIQUIDS,” U.S. ProvisionalApplication No. 62/705,538, filed Jul. 2, 2020, titled “METHODS ANDSYSTEMS FOR INLINE MIXING OF PETROLEUM LIQUIDS”, and U.S. ProvisionalApplication No. 62/954,960, filed Dec. 30, 2019, titled “METHOD ANDAPPARATUS FOR INLINE MIXING OF HEAVY CRUDE”, and, the disclosures ofwhich are incorporated herein by reference in their entirety. Thepresent application is further a Continuation-in-Part of U.S.application Ser. No. 17/247,704, filed Dec. 21, 2020, titled “METHODSAND SYSTEMS FOR INLINE MIXING OF HYDROCARBON LIQUIDS”, which claimspriority to and the benefit of U.S. Provisional Application No.63/198,356, filed Oct. 13, 2020, titled “METHODS AND SYSTEMS FOR INLINEMIXING OF PETROLEUM LIQUIDS,” U.S. Provisional Application No.62/705,538, filed Jul. 2, 2020, titled “METHODS AND SYSTEMS FOR INLINEMIXING OF PETROLEUM LIQUIDS”, and U.S. Provisional Application No.62/954,960, filed Dec. 30, 2019, titled “METHOD AND APPARATUS FOR INLINEMIXING OF HEAVY CRUDE”, the disclosures of which are incorporated hereinby reference in their entirety.

In the drawings and specification, several embodiments of systems andmethods to provide in-line mixing of hydrocarbon liquids have beendisclosed, and although specific terms are employed, the terms are usedin a descriptive sense only and not for purposes of limitation.Embodiments of systems and methods have been described in considerabledetail with specific reference to the illustrated embodiments. However,it will be apparent that various modifications and changes may be madewithin the spirit and scope of the embodiments of systems and methods asdescribed in the foregoing specification, and such modifications andchanges are to be considered equivalents and part of this disclosure.

What is claimed is:
 1. An in-line fluid mixing system positioned at atank farm to admix hydrocarbon liquids from a plurality of tanks into asingle pipeline, the in-line fluid mixing system comprising: a first setof tanks positioned at a tank farm with at least one tank containing ahydrocarbon fluid therein, each tank in the first set of tanks connectedto and in fluid communication with a first header, the first headerconfigured to transport a flow of one or more hydrocarbon fluids fromthe first set of tanks as a first fluid; a second set of tankspositioned at the tank farm with at least one tank containing ahydrocarbon fluid therein, each tank in the second set of tanksconnected to and in fluid communication with a second header, the secondheader configured to transport a flow of one or more hydrocarbon fluidsfrom the second set of tanks as a second fluid; a first pump having aninlet and an outlet, the outlet of the first pump connected to a firstbooster pipe and the inlet of the first pump connected to the firstheader to increase pressure of hydrocarbon fluid flow therethrough; afirst meter connected to the first booster pipe and configured tomeasure a first flow rate; a first spillback pipe having a firstconnection to the first booster pipe between the first meter and thefirst pump and a second connection to the first header upstream of thefirst set of tanks, the first spillback pipe including a first controlvalve disposed therein, the first control valve configured to adjust aflow rate of hydrocarbon flow through the first spillback pipe betweenthe first booster pipe and the first header; a second pump having aninlet and an outlet, the outlet of the second pump connected to a secondbooster pipe and the inlet of the second pump connected to the secondheader to increase pressure of hydrocarbon fluid flow therethrough; asecond spillback pipe having a first connection to the second boosterpipe downstream of the second pump and a second connection to the secondheader upstream of the second set of tanks, the second spillback pipeincluding a second control valve disposed therein, the second controlvalve configured to adjust a flow rate of hydrocarbon flow through thesecond spillback pipe between the second booster pipe and the secondheader; a blend pipe configured to admix hydrocarbon fluid that flowsfrom the first booster pipe downstream of the first meter withhydrocarbon fluid that flows through the second booster pipe downstreamof the first connection of the second spillback pipe to create a blendflow; and a blend meter connected to the blend pipe that measures flowrate of the blend flow through the blend pipe.
 2. The in-line fluidmixing system of claim 1, wherein the first spillback pipe includes afirst differential pressure transmitter (DPIT) positioned to measuredifferential pressure of hydrocarbon flow upstream and downstream of thefirst control valve and the second spillback pipe includes a second DPITpositioned to measure differential pressure of hydrocarbon flow upstreamand downstream of the second control valve.
 3. The in-line fluid mixingsystem of claim 2, wherein differential pressure measured by the firstDPIT is used to determine the flow rate of hydrocarbon flow through thefirst spillback pipe, and differential pressure measured by the secondDPIT is used to determine the flow rate of hydrocarbon flow through thesecond spillback pipe.
 4. The in-line fluid mixing system of claim 3,further comprising one or more controllers in signal communication witheach of the first control valve and the second control valve.
 5. Thein-line fluid mixing system of claim 4, wherein the one or morecontrollers controls an open percentage of the first control valve toadjust the flow rate of the hydrocarbon flow through the first spillbackpipe and thereby the first flow rate.
 6. The in-line fluid mixing systemof claim 4, wherein the one or more controllers controls an openpercentage of the second control valve to adjust the flow rate ofhydrocarbon flow through the second spillback pipe and thereby a ratioof first flow rate to blend fluid flow rate.
 7. The in-line fluid mixingsystem of claim 4, wherein the one or more controllers adjusts the firstcontrol valve to drive the flow rate of the hydrocarbon flow through thefirst spill back pipe toward a first set point flow rate.
 8. The in-linefluid mixing system of claim 4, wherein the one or more controlleradjusts the second control valve to drive the flow rate of thehydrocarbon flow through the first spill back pipe toward a second setpoint flow rate.
 9. The in-line fluid mixing system of claim 4, whereinthe one or more controllers adjusts at least one of the first controlvalve or the second control valve to drive a ratio of first flow rate toblend fluid flow rate toward a set point.
 10. A method of admixinghydrocarbon liquids from a plurality of sets of tanks into a singlepipeline to provide in-line mixing thereof, the method comprising:initiating a blending process that includes blending two or morehydrocarbon liquids over a period of time, at least one of the two ormore hydrocarbon liquids being stored in a tank of a first set of tanksand at least another of the two or more hydrocarbon liquids being storedin a tank of a second set of tanks, each tank of the first and secondsets of tanks being connected, via one or more pipes, to a blend pipethat is configured to blend the two or more hydrocarbon liquids into ablended hydrocarbon liquid; determining a density of each of the two ormore hydrocarbon liquids to be blended during the blending process; andupon initiation of the blending process: determining a first flow rateof hydrocarbon liquids flowing from the first set of tanks into theblend pipe; determining a blend flow rate of the blended hydrocarbonliquid in the blend pipe; determining a second flow rate of hydrocarbonliquids flowing from the second set of tanks into the blend pipe;determining a first spillback flow rate of a flow of hydrocarbon liquidsfrom the first set of tanks that is recirculated in a first spillbackloop positioned upstream of the blend pipe, the determining the firstspillback flow rate being based on a function of at least density of thehydrocarbon liquids that flow from the first set of tanks and adifferential pressure upstream and downstream of a first flow controlvalve disposed in the first spillback loop; determining a secondspillback flow rate of a flow of hydrocarbon liquids from the second setof tanks that is recirculated in a second spillback loop positionedupstream of the blend pipe, the determining the second spillback flowrate based on a function of at least density of the hydrocarbon liquidsthat flow from the second set of tanks and a differential pressureupstream and downstream of a second flow control valve disposed in thesecond spillback loop; and in response to a difference between a targetratio and a ratio of the first flow rate and the second flow rate:determining ratio adjustments for the first flow rate relative to thesecond flow rate; and adjusting the first flow control valve based onthe ratio adjustments to modify the first spillback flow rate therebyadjusting the first flow rate to drive the ratio towards the targetratio.
 11. The method of claim 10, wherein at least one of first flowrate or the second flow rate is determined based on the blend flow rate.12. The method of claim 10, wherein the flow of hydrocarbon liquids fromthe first set of tanks that is recirculated in the first spillback loopenters the first spillback loop downstream of a first pump and upstreamof the blend pipe, and wherein the flow of hydrocarbon liquids from thesecond set of tanks that is recirculated in the second spillback loopenters the second spill back loop downstream of a second pump andupstream of the blend pipe.
 13. The method of claim 10, wherein thedifferential pressure upstream and downstream of the first control valveis determined by a first DPIT, and wherein the differential pressureupstream and downstream of the second control valve is determined by asecond DPIT.
 14. The method of claim 10, further comprising adjustingthe second control valve to drive the second spillback flow rate towardsa set point.
 15. A controller for an in-line mixing system for admixinghydrocarbon liquids from a plurality of sets of tanks into a singlepipeline via spillback loops, the controller comprising: a userinterface input/output in signal communication with a user interfacesuch that the controller is configured to: (1) receive a target blendratio of a first liquid to a second liquid, (2) receive a first densityof the first liquid, and (3) receive a second density of the secondliquid; a first input in signal communication with a first meter tomeasure a first flow rate of the first liquid, the first meter beingconnected to a first pipe that is connected to a first set of tanks of atank farm, one or more tanks of the first set of tanks being configuredto store the first liquid of the first density and to transfer the firstliquid from the first set of tanks through the first pipe, thecontroller configured to obtain the first flow rate from the first metervia the first input after initiation of the blending operation; a secondinput in signal communication with a blend meter connected to a blendpipe to measure a blend flow rate of a blended liquid, the blendedliquid being the first liquid entering the blend pipe from the first setof tanks and the second liquid entering the blend pipe from a second setof tanks, the blend pipe being connected to the first set of tanks viathe first pipe and to the second set of tanks via a second pipe, one ormore tanks of the second set of tanks being configured to store thesecond liquid of the second density and to transfer the second liquidfrom the second set of tanks through the second pipe, the controllerconfigured to obtain the blend flow rate from the blend meter via thesecond input after initiation of the blending operation; a firstinput/output in signal communication with a first flow control device,the first flow control device designed to adjust recirculation of thefirst liquid via a first spillback pipe connected to the first pipe andpositioned upstream of the blend pipe, thereby modifying the first flowrate, the controller configured to: after initiation of the blendingoperation: determine whether the first flow rate is to be modified basedon at least two of the first flow rate, the blend flow rate, or thetarget blend ratio, and in response to a determination that the firstflow rate is to be modified: adjust an open percentage of the first flowcontrol valve that adjusts recirculation of the first liquid via thefirst spill back pipe, thereby modifying the first flow rate; and asecond input/output in signal communication with a second flow controldevice, the second flow control device designed to adjust recirculationof the second liquid via a second spillback pipe connected to the secondpipe and positioned upstream of the blend pipe, the controllerconfigured to: after initiation of the blending operation: determinewhether flow of the second liquid into the blend pipe is to be modifiedbased on at least two of the first flow rate, the blend flow rate, orthe target blend ratio, and in response to a determination that flow ofthe second liquid into the blend pipe is to be modified: adjust the openpercentage of the second flow control valve that adjusts recirculationof the second liquid via the second spill back pipe, thereby modifyingflow of the second liquid into the blend pipe.
 16. The controller ofclaim 15, wherein the open percentage of the first flow control valve isadjusted to drive the first flow rate toward a set point.
 17. Thecontroller of claim 15, wherein adjustment of the open percentage of thesecond flow control valve modifies flow of the second liquid into theblend pipe and drives blend ratio of the first liquid to second liquidin the blend pipe towards the target blend ratio.
 18. The controller ofclaim 15, wherein a first spillback flow rate is determined based on thedensity of the first liquid, a differential pressure across the firstcontrol valve, and open percentage of the first control valve, andwherein a second spillback flow rate is determined based on the densityof the second liquid, a differential pressure across the second controlvalve, and open percentage of the second control valve.
 19. Thecontroller of claim 18, wherein differential pressure is measured via aDPIT.
 20. The controller of claim 18, wherein differential pressure ismeasured via pressure sensors.